Concept:The error is a misuse of the verb "appear" where the verb "like" (to express preference) is needed.
Explanation:Part (a) says “appear like” which incorrectly suggests the herds seem to like West Bengal.
The verb “appear” means to come into sight or to seem, which does not convey preference.
The correct phrase should be “likes West Bengal” to show the herds’ fondness.
Thus the error is in part (a).
Parts (b) and (c) are grammatically correct.
The corrected sentence: “Migrating elephant herds like West Bengal so much that they spend more time here than in the neighbouring states from where they cross over.”
Answer:The error is in part (a). So the correct option is (a).