While __________ is the fastest unsaturated logic gate __________ has the excellent noise immunity?

While __________ is the fastest unsaturated logic gate __________ has

1.	While __________ is the fastest unsaturated logic gate __________ has the excellent noise immunity?
A.	ECL, TTL
B.	TTL, ECL
C.	ECL, RTL
D.	RTL, DTL
Answer» D. RTL, DTL