Select the most appropriate option to fill in the blank.

Plenty of information about the flora and fauna of India ______ available in this book.

is

The correct answer is is.

The sentence is about the availability of information about the flora and fauna of India in a book. The verb to be is used in the singular form because the subject of the sentence is singular (information). The present tense is used because the information is still available in the book.

The other options are incorrect.

• Are is plural and does not agree with the singular subject of the sentence.
• Has is singular but is used in the present perfect tense, which is used to describe actions that have happened in the past and have a lasting effect on the present. In this case, the information about the flora and fauna of India is still available in the book, so the present perfect tense is not appropriate.
• Were is plural and is used in the past tense, which is not appropriate for this sentence.