An overloaded subtraction operator subtracts two Shipment objects from each other, returning an integer that represents the difference in their totalWeight variables. The subtraction operator works as...

An overloaded subtraction operator subtracts two Shipment objects from each other,

returning an integer that represents the difference in their totalWeight variables.

The subtraction operator works as expected, with the object to the right of the

minus sign being subtracted from the object to the left. The function header is int

Shipment::operator-(Shipment ship). Within the function, which of the

following is correct?

a. int difference = ship – totalWeight;

b. int difference = totalWeight – ship;

c. int difference = ship.totalWeight – totalWeight;

d. int difference = totalWeight – ship.totalWeight;