Question

Delhi sultanate reached the peak of its power during the rule of_______?
A. Balban
B. Alauddin Khilji
C. Firoz Tughlaq
D. Raziya

Answer 1

Hint:
He was the first ruler of Delhi sultanate who was successful in conquering the Deccan and South India.
His dynasty was longest in the chair of rulers in Delhi sultanate.
Mohammed Ghori created an empire, which is understood as Delhi sultanate and was in power from 1206 AD to 1526 AD.

Complete answer:
Balban:

Ghiyasuddin Balban I belong to an elaborate Turkish tribe. His original name was Baha ud din. He was crowned as a king from 1266 to 1287. He dismantled the Chalisa group of nobles.
Established a very efficient system of espionage and built a separate military department called diwan I Ariz.
Balban ruled with a policy of blood and iron. He started to celebrate Persian new year called ‘Navroz’
He Ordered for Sijda (prostration) and paibos (kissing of feet) because of the usual kind of king's salutation.
He banned courtiers and officers from drinking, joking, laughing and even smiling. He also gave up drinking wine and enjoying.

Alauddin Khilji:

Alauddin Khilji was a second ruler of the Khilji dynasty assumed the throne in October 1296 he faced the largest number of Mongol invasions.
Conquest of Alauddin Khilji includes the expedition to devagiri, Gujarat, Ranthambore, Chittoor, Warangal, Pandya dwarasamudra.
Alauddin was the first ruler of Delhi sultanate who was successful in conquering the Deccan and South India.
He maintained a huge regular army.
Alauddin Khilji introduced the market regulations to assist soldiers and to create ends meet.
Alauddin Khilji developed a land calculation methodology for calculating land revenue. Jizya was imposed on non-Muslims. They will have to pay it along with other taxes, such as pilgrim fee, toll, etc.
 In order to avoid false trends and unethical practices, he implemented the method of branding horses (dagh) and keeping a descriptive register of soldiers.
Due to his extensive conquests and market reforms, Delhi sultanate reached its height during the reign of Alauddin Khilji.

Firoz Shah Tuglaq:

Firoz Shah Tughlaq was in power from 1351 to 1388 AD.
He made military post hereditary, a soldier can send his child when he wants to take leave from services. Payment to soldiers was made in land grants instead of money.
He built numerous canals for an efficient irrigation system, also levied Haqi-i-shirb,an irrigation tax.
 His Contributions include Establishment of the Diwan-i-Khaira and Diwan-i-Bandagan.
Four new towns have been established: Firozabad, Fatehabad, Jaunpur and Hissar.
He was the first ruler to establish a government. hospitals called Dar-ul-Shifa Or Shifa Khana.

Raziya:

Raziyat-ud-din commonly referred to as Razia Begum or Sultana Razia was the daughter of shams ud din Iltutmish.
She was the primary and also the last woman among the varied dynasties that occupied the throne of Delhi. She ruled from 1236-40.
She used to dress up as a man in an outfit called kulah and sat in an open durbar. She was an efficient and just ruler and had characteristics of an efficient monarch.
It has been said had Razia not been a woman, she would be one among the foremost successful rulers of India.

Therefore, the correct answer is B

Note:
Dynasties of Delhi sultanate

Slave Dynasty (1206-1290)
Khilji Dynasty (1290-1320)
Tughlaq Dynasty ( 1320-1412)
Sayyid Dynasty (1414-1450)
Lodhi Dynasty (1451- 1526)

Ministries during the sultanate period

Diwan i ariz - military department
Diwan-i-Khairat - office for charity
Diwan-i-Bandagan - department of slave