Asynchronous Down Counters

Multiple Choice

Asynchronous down counters:

A) require that the LSB flip- flop change states with each input clock pulse the same as an up counter.
B) require that the MSB and LSB flip- flops change states with each input clock pulse.
C) require that the MSB flip- flop change states with each input clock pulse the same as an up counter.
D) require that each flip- flop change states with each input clock pulse.