Select the most appropriate option to fill in the blank.
Do you think he is old ______ to participate in this competition.

Correct option is B

The correct option to fill in the blank is (b) enough.
Explanation: The pattern is adjective + enough + to-infinitive to show sufficiency: “old enough to participate” = उतना बड़ा/पर्याप्त रूप से बड़ा कि भाग ले सके. “Too” expresses excess leading to a negative result ( too old to… would imply cannot), while “rather/quite” do not express sufficiency.
Example: She is strong enough to lift the box.
Explain why other options are incorrect.
· (a) too: indicates excess resulting in an undesired outcome (बहुत ज़्यादा) — meaning would change.
· (c) rather: somewhat/quite (काफ़ी/कुछ हद तक) — not a sufficiency marker with “to + V”.
· (d) quite: fairly/completely depending on context (काफ़ी/पूरी तरह) — doesn’t license “to + V” for sufficiency.
Information booster (degree + enough): With adjectives/adverbs, enough follows them (e.g., fast enough), but with nouns it precedes ( enough money).