Hint: Plough is a tool which is used to dig the soil to yield good production of crops and it is used to make the furrows for planting. A cultivator is a kind of farm tool which is used for secondary cultivation.
-Plough: A plough is a tool used by the farmers in case of loosening or turning the soil before sowing the seed or planting saplings. In ancient times the plough is used by the oxen but in modern times it is done by the tractors. The main importance of plough is to smooth the uppermost soil so that the fresh nutrients and minerals from the soil come out and produce the high yielding and of good quality of crops. There was a type of plough known as moldboard plough which was used to grow crops in less fertile soil. A plough may consist of a wooden, iron, or steel frame with blades attached which is used to cut the soil. The plough cut about 12 to 25 cm deep into the soil where the most root grows. The main disadvantage of using plough is as it reduces the organic matter such as humus and also changes the shape of the soil.
-Cultivator: Cultivators blend and grind the soil either before planting for the oxygenation of the soil and prepare a smooth, loose seedbed or after the growing of the crop to kill weeds. Cultivators are generally either self-propelled or found in the attachment with the two-wheel tractor or a four-wheel tractor. Cultivators of the toothed type are as same as plough but their goals are different.
Hence, the correct answer is B.
Note: The idea of ploughing was developed by John Fowler in the mid-19th century. There are several types of plough which are used such as disc type plough, rotary plough, etc. The cultivator generally consumes less energy compared to the plough.