When the less than ( < ) operator is used between two pointer variables, the expression is testing whether: a. the value pointed to by the first is less than the value pointed to by the second.
b. the value pointed to by the first is greater than the value pointed to by the second.
c. the first variable was declared before the second variable.
d. the address of the first variable comes before the address of the second variable in the computer's memory.
d. None of the above