You can't listen to other sounds and retain them while you are speaking.
The correct answer should be additionally.
The word additionally would provide the best transition between these two sentence. It is so because you have one idea in the first sentence, and then you want to show another idea very similar to the first one in the second sentence. Using additionally to convey that is the way to go.
Use transition words to make your writing flow
The answer is letter B<span> - The speaker is sleeping and is awakened by someone calling to him.
</span><span>When the speaker says, "While I nodded, nearly napping, ..." he is sleeping, because when you're about to sleep you'll usually nod your head back and forth right when you're drifting off.
Answer: Letter B
Hope that helps. -UF aka Nadoa</span>
