Four MSI TTL 4-bit ripple counters are cascaded to form a 16-bit binary counter. Its propagation delay is about __________ nanoseconds.

Four MSI TTL 4-bit ripple counters are cascaded to form a 16-bit binar

1.	Four MSI TTL 4-bit ripple counters are cascaded to form a 16-bit binary counter. Its propagation delay is about __________ nanoseconds.
A.	70
B.	140
C.	210
D.	280
Answer» E.