Final answer:
The correct sentence is A) The remains of the body were thrown into the sea.
Step-by-step explanation:
The subject of the question is English Grammar.
The correct sentence is A) The remains of the body were thrown into the sea. 'Remains' is the plural form of 'remain', which correctly matches with the plural verb 'were'.
The incorrect options are B) The remain of the body was thrown into the sea, C) The remains of the body were thrown to the sea, and D) The remains of the body was thrown into the sea. These options have subject-verb agreement errors.
Learn more about subject-verb agreement