Jack likes baseball as much as I s the pronoun used incorrectly.
c)Jack likes baseball as much as I.
Explanation:
This sentence should be rephrased to Jack likes baseball as much as me. Generally, A pronoun is a word that replaces a noun in a sentence. There are several different kinds of pronouns and they are:
Common pronouns are I, me, mine, she, he, it, we, and us. Hence it helps to frame a clear sentence. They usually refer back to a noun used earlier in the sentence, and they must match the number, point of view, and gender of the noun. So the pronoun should be rephrased to me instead of I.