In Markus' (1978) Research in Which Participants Had to Do

In Markus' (1978) research in which participants had to do an easy or hard task alone or before an audience, what was found?

A) The easier task took LESS time with an audience than when alone.
B) The harder task LESS time with an audience than when alone.
C) The harder task MORE time with an audience than when alone.
D) Both a and c.