"I gave him my address."
Translation:Yo le di a él mi dirección.
I'm not sure why you're answers are marked wrong, but maybe it's because your sentences translate to "I gave my address to him," vs. "I gave him my address." Hmm...
I don't understand why you need the "él" in this sentence. Doesn't the "le" already tell you that it's being given to him? (Or does it require the "él" to specify that it's being given to a 'him' and not a 'her' or 'it'?)