Identify the Adjective clause in the following sentence:

I believe this is the place where our fore fathers landed, isn't it?

Where our fore fathers landed

The correct answer is Option (3) - Where our fore fathers landed

Reasoning:
An Adjective Clause is a group of words that contains a subject and a verb and modifies a noun or pronoun in the main clause.

In the sentence —

I believe this is the place where our forefathers landed, isn't it?

The clause "where our forefathers landed" describes the noun "place" by telling which place.

Hence, "where our forefathers landed" is the Adjective Clause.