The passage given below has numbered blanks. Choose the word that best fits Blank 1.
Over the past decade, the sunflower sea star has gone from a predator of the Pacific Ocean to nearing extinction. The Nature Conservancy estimates that 5.75 billion sunflower sea stars died over three years, a 94% global (1) _____________. The cause, scientists say, is largely climate change and warming waters, (2) ________________ by sea star wasting disease. Hope is slowly on the horizon. The Birch Aquarium at Scripps Institution of Oceanography near San Diego successfully (3) _______________ three sunflower sea stars recently, the latest success story in a sprawling collaborative effort. TBA has five sunflower stars, one of the largest populations of sunflower stars in (4) _______________ in California. But until recently it did not know their gender. To determine the sex, researchers induced spawning. After further testing, they can determine whether the (5) ___________________ could survive disease or parasites. Once that’s done, the aquarium will be able to begin the fertilization process.

Correct option is D

The correct option to fill in the blank is (d) Decline.
‘Decline’ means a decrease or reduction in number or value. (गिरावट)
Example: The population of vultures has seen a sharp decline over the past two decades.
Explanation: The sentence talks about a catastrophic event — the death of 5.75 billion sunflower sea stars, indicating a 94% reduction. Hence, 'decline' fits perfectly.
Explain why other options are incorrect:
· Fallout: Result or consequence of an event, especially a harmful one (परिणाम)
· Increase: A rise or growth in number or size (बढ़ोतरी)
· Spurt: A sudden short burst or increase (तेज़ उछाल)