Which of the following statements accurately describe the condition that can be used for conditional compilation in C++?
A. The condition can depend on the value of program variables.
B. The condition can depend on the values of any const variables.
C. The condition can use the sizeof operator to make decisions about compiler-dependent operations, based on the size of standard data types."
D. The condition can depend on the value of environmental variables.
E. The condition must evaluate to either a "0" or a "1" during pre-processing.