In the following passage, some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.

The rise in the Irrawaddy dolphin (1) ______ in Chilika can be attributed to the eviction of (2) ______ fish enclosures. After thousands of hectares of Chilika lake were made (3) ______ free, Irrawaddy dolphins found unobstructed area for movement. (4) ______, due to the COVID-19 lockdown last year, there were comparatively fewer tourist boats on Chilika lake, which made it (5) ______ for dolphins to move from one part of the lake to another.

Select the most appropriate option to fill in blank no.3.