Luka$$s English paper is returned, and on the second page of his paper, the sentence $"$An important part of my life have been all the books I read in college." is circled in red with the note "verb agreement" written in the margin because he should correct the sentence and use the word $$has$$ instead of the word $$have$.$ The error in the sentence is based on

Group of answer choices

grammar rules.

syntax rules.

transformation rules.

context rules.