"She was absent due to a family emergency."

The correct answer is Option (1) → Adverb of Reason

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.

The underlined words due to a family emergency are a phrase, a group of words with no verb of its own. This phrase does the work of one adverb. It gives the reason she was absent. An emergency is a sudden, serious problem that needs quick action.

Option	What it tells	Example
(1) Adverb of Reason (answer)	answers the question why?	The train was late due to heavy fog.
(2) Adverb of Time	when something happens: the underlined words do not say when she was absent	The shop opens early on Sundays.
(3) Adverb of Place	where something happens: no place is named here	The boys are playing cricket nearby.
(4) Adverb of Manner	how an action is done	The baby smiled sweetly at her mother.