Respuesta :
c is correct. As Tina’s skill at studying increased, her grades improved.
Answer:
C. As Tina's skill at studying increased, her grades improved.
Explanation:
We use apostrophes to show ownership or to form contractions. Here, we just want the plural version of grade, aka "grades," so an apostrophe is not needed. Thus, options B and D, which put an apostrophe somewhere in "grades" are incorrect.
We only place an apostrophe at the end of a noun if the noun is plural. For example, "The two boys' pencils were missing." But here, Tina is just one person, so option A is wrong because it makes it sound like there is more than one Tina.
So that leaves us with option C, "As Tina's skill at studying increased, her grades improved." It correctly adds -s to Tina and does not put an unnecessary apostrophe in grades.
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