The correct option is
D All of these
Explanation for the correct option:
(D) All of these
- Threshing is the method used to extract grain from stalks.
- Threshing can be done by following methods:
Threshing by beating :
- This is the most adopted method for the extraction of grains.
- The crops are beaten against solid objects like ground, walls, etc.
Threshing by Bullocks :
- Bullock treading is an ancient technique used in India where the crop is put out on the threshing floor in a circle and bullocks are forced to walk over it in a circular manner.
- Bullock's feet are repeatedly tramped on, which causes threshing.
Threshing by Machines :
- The grain is separated from straw and other light components using a threshing machine.
Explanation for the incorrect options:
Since, all the methods given in options (A), (B) and (C) are used to do the threshing. Therefore, only option (D) is correct, that is all of these.