Gilbert Thought He Could Detect the Faint Odor of Smoke

Multiple Choice

Gilbert thought he could detect the faint odor of smoke coming from the room next door.However, he wasn't really sure because the odor was very faint and when he tried to smell it again it seemed to have disappeared.Based on research conducted by psychophysicists, you should conclude that the odor from the smoke was:

A) below Gilbert's difference threshold for smell
B) above Gilbert's adaptation threshold for smell
C) below Gilbert's level for perceptual invariance
D) just at Gilbert's absolute threshold for smell