The telephone ...... several times before I answered it.

Answer: Option A

The telephone was ringing several times before I answered it.
In this context, the past continuous tense "was ringing" is used to describe an ongoing action that was happening in the past at the time when another action (answering the telephone) occurred. Therefore, "was ringing" is the most appropriate choice to complete the sentence, indicating the continuous action of the telephone ringing before it was answered.