The correct answer is d) Banana co;
Explanation:
In Java everything is an object, for example when we declare a variable x of type int we usually do in this way, determine the class we are going to instance and then the name of our object:
int x;
On the example above we instantiate an object of int named x.
For this exercise we have to instantiate an object of type Banana that is going to be named co.
Banana co;