Technician a Says That with a Vacuum Leak, an Engine

Multiple Choice

Technician A says that with a vacuum leak, an engine with an oxygen sensor feedback fuel system can run fine when cold but rough when hot. Technician B says that advanced ignition timing will often cause an engine to run hot. Who is right?

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