From the options given below, choose one word for the following expression

Event happening every four years.

Quadrennial

The correct answer is Option (3) → Quadrennial

Quadrennial refers to something that occurs once every four years.

Option (1) → Annual: Occurring once every year.
Option (2) → Biennial: Occurring once every two years.
Option (4) → Triennial: Occurring once every three years.