Final answer:
B) The memory address of the variable called num1. The statement cout << &num1; will output the memory address of the variable called num1.
Step-by-step explanation:
The statement cout << &num1; will output the memory address of the variable called num1. The & symbol is used to denote the address-of operator in C++. When we use &num1 with the cout statement, it will print the memory address where the variable num1 is stored.