Fill in the blank in the following sentence with the most appropriate…

The correct answer is Option (4) → any other

An adjective is a word that describes a noun or a pronoun, for example a tall tree, the food is tasty.

Complete sentence: Yamuna is more polluted than any other river in this country. The Yamuna is one of the rivers of the country, so it is "more polluted than any other river".

Option	What it tells	Example
(1) other	A singular countable noun such as "river" needs a determiner before "other" (any, the, every). "Than other river" is not correct.	Do you have any other idea?
(2) all other	"All other" takes a plural noun (all other rivers). "River" is singular.	All other students had left.
(3) all of the	"All of the" also needs a plural noun (all of the rivers), and without "other" it would include the Yamuna itself in the comparison.	All of the rivers were in flood.
(4) any other (answer)	When one member of a group is compared with the rest of the same group using a comparative (more polluted than), the pattern is comparative + than + any other + singular noun. "Other" leaves the thing itself out of the comparison, so it is not compared with itself. Deciding clue: "more polluted than ... river": a comparative with a singular noun of the same group. Two-step check: 1. number: singular "river" → any other / other. 2. A singular countable noun needs a determiner → any other.	Mumbai is bigger than any other city in Maharashtra.