Correct option is D
The correct option to fill in the blank is (d) Important.
Explanation: The adjective "important" correctly modifies the noun "thing" in the sentence, describing what is most valuable in Laxmi's life.
Meanings of other options:
· Importancy: Incorrect, as this form is rarely used.
· Importance: A noun, not suitable as an adjective in this context.
· Importantly: An adverb, which is inappropriate here.