The following sentence has been split into four segments. Identify the segment that contains a grammatical error.
I am very much / obliged of my friend / for the help / he rendered to me.

The correct answer is obliged of my friend.

Explanation:

In the given sentence, the phrase "obliged of my friend" contains a grammatical error related to the use of prepositions.

The adjective obliged (meaning thankful or grateful) is followed by the preposition to when indicating the person to whom gratitude is owed, and by for when indicating the cause or reason for gratitude (e.g., "obliged to someone for something").

Therefore, the preposition of is incorrect here and should be replaced by to.

Correct Sentence:
"I am very much obliged to my friend for the help he rendered to me."