The correct options are
A Potato and tomato
C Rotten and fresh fruits
D Oranges and apples
Handpicking is a method of separation. It is used when the difference between the components is clearly visible like size, shape, colour, etc. Also, the particle size should be large enough to get hand picked.
Potato can be separated from tomato, rotten fruits from fresh ones and oranges from apples by handpicking.
Since, salt and sand particles are too fine in size, they cannot be seperated by handpicking.