Your choices were the following:

• (a) Console your friend.
• (b) Cry.
• (c) Jump up and down and shout incoherently.
• (d) Sing, "Ding dong, the witch is dead."

(a) may feel like a good response, but if you're trying to be a funny person, it won't help you. (b) is wrong for the same reasons. (c) would seem to be an unexpected response, and in that way funny -- however, grief manifests itself differently in many people. Your attempt at humor might be mistaken for honest grieving, so your joke would be lost on your friend. (d) is the correct answer because it would cause your friend pain, would be unexpected, and referring to the mother as a "witch" could possibly be a lie.