Find out whether there is any grammatical error in below sentence. Since I had been gone / through the book / long back, I could / not remember the contents.

The correct answer is: E. No error

The sentence is grammatically correct.

The word “since” is used to introduce a clause that expresses a reason or cause. The word “gone” is the past participle of the verb “go,” and it is used here as an adjective to modify the noun “book.” The word “through” is a preposition, and it is used here to indicate that the speaker has read the book from beginning to end. The word “long back” is an adverb, and it is used here to indicate that the speaker read the book a long time ago. The word “could” is the past tense of the verb “can,” and it is used here to indicate that the speaker is no longer able to remember the contents of the book. The word “not” is a negative adverb, and it is used here to negate the verb “remember.” The word “contents” is a noun, and it refers to the information that is contained in the book.

The sentence is clear and easy to understand. It does not contain any errors in grammar, punctuation, or spelling.