Greenwald, et al., (1991) conducted a double-blind study on the effectiveness of subliminal self-help audiotapes

In their study, participants listened to one of two self-help tapes that (ostensibly) presented
messages designed to aid memory or self-esteem. However, the memory tape was labeled "self-esteem" and the
self-esteem tape was labeled "memory improvement." Later they were assessed on actual improvement in self- esteem or memory, as well as their own perceived improvement in self-esteem or memory. What was found?
a) There were actual improvements, and these improvements matched the content of the tape.
b) There were only perceived improvements, and these improvements matched the content of the tape.
c) There were actual improvements, and these improvements matched the label of the tape.
d) There were only perceived improvements, and these improvements matched the label of the tape.

Answer: d