The correct options are
A Weeding is a necessary step in agriculture.
B Weeding is the process of removal of weeds.
C Weeding should be done before weeds mature.
Weeding is the process of removal of weeds (unwanted plants) in an agricultural land. It is a necessary step in agriculture as the weeds might start competing with the crop plants for water, nutrients, sunlight, etc. Weeds adversely affect the growth of the crop. The best time for the removal of weeds is before they produce flower and seeds (mature). So that they do not interfere with the harvesting process. Weeding can be done manually using tools like khurpi or chemically by using weedicides.