Parts of the following sentence have been given as options. Select the option that contains a grammatical error.
The scientists have concluded that their research shows a correlation between air pollution and the decline in bird populations, and they recommends immediate action to reduce emissions.

Correct option is A

The error is in "and they recommends immediate action to reduce emissions."
Explanation:
· Subject-Verb Agreement Rule:
· "They" (plural subject) should be followed by "recommend" (plural verb), not "recommends" (which is singular).
· Correct sentence: The scientists have concluded that their research shows a correlation between air pollution and the decline in bird populations, and they recommend immediate action to reduce emissions.
Incorrect Options:
· (b) The scientists have concluded that (Correct structure.)
· (c) and the decline in bird populations (Correct phrase.)
· (d) their research shows a correlation between air pollution (No error.)
Example:
· She recommend a new policy. (Incorrect)
· She recommends a new policy. (Correct)
· They recommend a new policy. (Correct)