9C15 D
 In order of highest to lowest speed, the logic families are ranked:
A. ECL, CMOS, Schottky TTL, Standard TTL.
B. Schottky, Standard TTL, ECL, CMOS.
C. CMOS, Standard TTL, Schottky TTL, ECL.
D. ECL, Schottky TTL, Standard TTL, CMOS.
