There Were Two Independent Variables in the Loftus and Colleagues

There were two independent variables in the Loftus and colleagues (1978) experiment.What were they?

A) what type of traffic sign they saw and whether the question they were asked matched or didn't match the sign they saw
B) what sign they identified as seeing from a group of 30 slides and what type of traffic sign they saw
C) whether or not a gorilla walked past the traffic sign and what kind of car was in the pictures
D) whether the question they were asked matched or didn't match the sign they saw and whether the driver was Black or Hispanic