Philip has been in training for several months and now plans to run in the school-sponsored, ten-mile, fun run mini-marathon. He completes and signs an entry blank which contains the statement, "I hereby agree to hold the sponsors harmless for any injury sustained as a result of participation in this event no matter how such injury may be caused."

a.

What is the legal term for this clause in the agreement?

b.

Is the clause valid and legally enforceable? Explain its legal effect.