Read the given passage and answer the four questions that follow:-

Till recently, many scholars have worked on collections of folk songs, but their main attention was on their lyrical content. The musical aspect just did not receive so much attention. Hence, the subject remained a closed book. When I ventured to study the subject, I faced the stark fact that the only source available to me was the rustic folk themselves. The difficulties for such a primary worker in any field are very well-known. But the co-operation I had from the simple men and women of the villages made me forget everything. With the deepest love and gratitude to the village folks, I present to you some fragments of my collection and humble observations on them.

Now, who are these folks? I would say that they are the "civilized" people of the villages. They are a group in whom the economic, educational and cultural diversity of the city is much less pronounced. Their modes of life, customs, lore and songs are known and shared by one and all in the group. Their art, particularly their music, is the expression of their thoughts, feelings, hopes and aspirations. Their music is simple, natural and free from any kind of artificial sophistication or inhibition, which is an unavoidable feature of any urban society.

Tamilnad abounds in the beauties of nature in all its vicissitudes, hills and dales, plains and pasturage. Its magnificent temples have fostered arts like architecture, sculpture, music, dance, painting and literature. It is of interest to note that folk arts, culture and tradition had a great part to play in the development of these.

Select the appropriate option for the underlined phrase given below:-

'The subject remained a closed book.'

Nothing much is known

The correct answer is Option (3) → Nothing much is known

The idiom 'a closed book' means a subject or person about which one knows nothing or little.

In the context of the passage: "Till recently, many scholars have worked on collections of folk songs, but their main attention was on their lyrical content. The musical aspect just did not receive so much attention. Hence, the subject remained a closed book."

The author is stating that because scholars focused only on the lyrics and ignored the music, the musical aspect of folk songs remained a mystery or an unknown field of study. Therefore, nothing much is known about it.