Out of given options choose a word that can be used as an adjective as well as an adverb.

Fast

The correct answer is OPTION 1 -FAST

• Fast as an adjective: "He drives a fast car." (Describes the car)
• Fast as an adverb: "He runs fast." (Describes the manner of running)

Other options do not fit:

• Quickly: Adverb only.
• Beautiful: Adjective only.
• Happily: Adverb only.