Select the option that will improve the highlighted part of the given sentence.
She is kindest than anyone.

Correct option is D

The correct substitution of the highlighted words is (d) kinder.

Explanation:
The sentence uses the conjunction 'than', which indicates a comparison between two entities (She and anyone else). Therefore, the comparative degree 'kinder' must be used instead of the superlative 'kindest'.

Grammatical rule used: Comparative adjectives are used to compare differences between the two objects they modify. The structure is usually: [Noun (subject) + verb + comparative adjective + than + noun (object)].

Example: This room is bigger than the other one.

Information Booster:
Superlative degrees (kindest, biggest) are used when comparing more than two things and are usually preceded by 'the'.

So the correct answer is (d)