Answer:
Mechanical advantage in this situation is equal to 1.
Step-by-step explanation:
The mechanical advantage of a simple machine gives a relationship between the input force applied to the output force. Mathematically, it is given by :

Where
are output force and input force
In this case, the weight of the crate of vegetables is 100 N
Force exerted by her to lift the crate with a pulley is 100 N
The mechanical advantage in this situation is given by :

So, the mechanical advantage in this situation is equal to 1. Hence, the correct option is (b) "equal to 1".