Hint: The Archeological department is the one responsible for all the activities to study and understand our past whether it be the monolithic age or the stone age. Archeologists are the ones who study and understand the past as a series of events and today's situation as yesterday’s cause.
Complete answer: There are several ways in which history could be studied and many if it depends on the remains and ruins that are available for us to study. The remains are dated back using carbon dating and then their age is determined giving us an approximate idea from where the object comes and what its history is. All the objects which are from the past give us a lot of information about the lifestyle of the people, their activities and functions during the period etc. From the invention of the wheel to different settlements that took place in history were all studied by analyzing the remains that were obtained in the specific place after archeologists decided to dig it up. Ancient people used bones of the animals as souvenirs and they stored seeds and food grains separately. These storage sites are still very much present to this day and have given us a lot of information about the stone age. The drawings they made on caves, the houses they built to escape floods and other emergency situations in settlements like Harrapan Valley are all evident examples of how we as humans evolved over years.
After the stone age, kings and emperors took over different lands and each king had his own type of alloy and currency undertaken for his specific kingdom. The seal was specific to the kingdom and often considered the pride of the king because it was his emblem.
Hence, the correct answer is option (D).
Note: Remains of food grains, seeds and bones of animals are artifacts that were found in different settlements , don’t get confused on different means to study the history as all of the above statements are true. There are still several kingdoms and forts which are under Archeological survey of India which shows us our rich history.