Which statement about cost allocations is true?

Which statement about cost allocations is true?

A.
A cost allocation can have a fixed amount, and the total allocation percentage is always
100.

B.
A cost allocation can have a fixed amount and a time period applies to cost allocations.

C.
The total allocation percentage is always 100, and a time period applies to cost
allocations.

D.
Cost allocations can be nested, and a cost allocation can have a fixed amount.