Technician a Looks for Engine Speed (RPM) When Cranking an Engine

Multiple Choice

Technician A looks for engine speed (RPM) when cranking an engine that will not start. Technician B says that a problem in the primary circuit could make the tachometer not work. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B