Since putting 8 sticks in each lunch box doesn't give any leftover, that means that number of carrot sticks she had is a multiple of 8.
Pretty simply!
Let's see the multiples of 8.
Multiples of 8: 8, 16, 24, 32, 40, 48, 56, 64, ....
Out of the choices, only 48 is a multiple of '8'.
Therefore,
D is correct
