The sentence is in the present perfect continuous tense, which requires the verb in the "-ing" form to indicate an ongoing action.
The correct sentence should be:
"He has been listening to music for the past hour."
Thus, the correct answer is (A) "listening."
Each question has a sentence that has an underlined part. Choose the option which rephrases the underlined part in the most appropriate manner in terms of grammar and usage.
In an attempt to boost their profits, many edible oil-producing companies have been engaging themselves in propaganda against commonly used oils and promoting exotic and expensive varieties of oils \(\underline{as\ more\ healthier\ options.} \)