Select the most appropriate synonym of the highlighted word.
No one was prepared for the environmental calamity that hit the town in the middle of the night.

Correct option is D

The correct synonym of the given word is catastrophe.
Calamity: A great misfortune, disaster, or sudden damage causing loss and distress. (आपदा, विपत्ति)
Example: The earthquake was a terrible calamity that destroyed many homes.
Catastrophe: A sudden event causing great loss, damage, or suffering. (विनाशकारी आपदा)
Example: The flood turned into a national catastrophe.
Synonyms: disaster, tragedy, cataclysm, mishap
Antonyms: blessing, miracle, salvation, fortune
Meanings of other options:
·  (a) Stress – Emotional or mental strain. (तनाव)
·  (b) Degradation – Decline in quality or value. (गिरावट)
·  (c) Damage – Harm or injury, but less intense than “calamity”. (नुकसान)