Question

Fill in the blank with the most appropriate word.
A river ________ is polluted is not safe for swimming.

• A. whose
• B. where
• C. when
• D. which

Answer 1

The correct option is D which

Relative pronouns have two functions. Like other pronouns they stand for the noun or pronoun places before them and like conjunction they join sub clauses with main clause and start the adjective clauses.

In the given sentence the subject is a river.

The relative pronoun 'whose' is used for persons; 'where' and 'when' can sometimes be used as a relative pronoun to indicate place and time respectively; 'which' is used in case of things and non-human objects.

Since the given sentence talks about a river, 'which' must be used.

Thus option D is the correct answer.

Options A,B,C are incorrect.