The present continuous tense is formed with the Subject plus Auxiliary verb(is/am/are) plus the present particle form (-ing) of the main verb.
In this particular sentence, we can understand that the question is based on something which is happening. The present continuous tense is a grammatical tense that can be used to describe when an action is happening. So, we would be using Present Continuous Tense for the given blank.
Option 'A' "were" is the past forms of verbs, it is the wrong option.
Option 'B' "Will" is used in Future Tense, it is the wrong option for the given question.
Option 'D' 'Have you listened' refers to the completed action, it does not fit in the given sentence.
Hence option C is the correct answer