A MOD- 8 Asynchronous Counter Has a "Worst Case" Propagation

Multiple Choice

A MOD- 8 asynchronous counter has a "worst case" propagation delay of t_phl = 37 ns. The maximum input clock frequency for this counter would be:

A) 6.756 MHz
B) 13.514 MHz
C) 9.009 MHz
D) 5.405 MHz