I said ummm who is this ? ? ? He tried deepening his voice and said " This is Bob . " I said Ah Bob ? ? so we hung up and since I do nt like liars , I called him back and said Hey Just to let you know , If your going to make up a fake name , Least let it be convincible .

Question: Why did the man try deepening his voice ?
Answer: Because the writer asked who it was .Because his name is Bob .None of the above choices .He wanted to pretend he was someone else .