She smiled __________ upon seeing her old friend.

The correct answer is Option (1) → warmly

An adverb is a word that tells how, when, where or how much something happens. It can also describe an adjective or another adverb, for example she sings sweetly, very hot.

Complete sentence: She smiled warmly upon seeing her old friend. The blank tells how she smiled, so it needs an adverb.

Option	What it tells	Example
(1) warmly (answer)	in a kind and friendly way that shows you are happy	Dadi warmly welcomed the guests at the door.
(2) melodiously	in a sweet, musical way: it is used for singing and sounds, and a smile makes no sound	The koel sang melodiously in the mango tree.
(3) easily	without any difficulty: it tells nothing about the feeling in her smile	Aman solved the sum easily.
(4) quickly	fast: meeting an old friend calls for a friendly smile, and speed adds nothing here	He quickly packed his bag and left.