Select the Answer That Joins Each Pair of Simple Sentences

Multiple Choice

Select the answer that joins each pair of simple sentences with conjunctions or conjunctive adverbs correctly and is punctuated correctly. Arthur was anxious about the benefit dinner.
Only twenty people had responded to the invitation.

A) Arthur was anxious about the benefit dinner because only twenty people had responded to the invitation.
B) Only twenty people had responded to the invitation for Arthur was anxious about the benefit dinner.
C) Since only twenty people had responded to the invitation Arthur was anxious about the benefit dinner.