In Some Stage Acts, a Hypnotist Shows That a Hypnotized

In some stage acts, a hypnotist shows that a hypnotized person can become as stiff as a board, balancing with the head on one chair and the feet on another. How is this done?

A) People can do this even without being hypnotized.
B) The hypnotist puts the audience into a trance so they think they see something they do not see.
C) Hypnotism gives people greater than normal strength.
D) The person's weight is supported by very thin wires that the audience cannot see.