Correct Answer: acceptable

Solution : The correct answer is option 1.
Explanation:

The adjective ' acceptable ' modifies the noun 'grades'.

• ' Acceptance ' is the noun form of the word in brackets and a noun cannot modify another noun 'grades'.
• -Likewise, ' acceptability ' is a noun.
• - Accept is a verb that refers to an action, whereas the question requires an adjective.
• - As a result, to make the sentence grammatically proper, the word ' acceptable ' should be employed.
• - As a result, 'acceptable' is the correct answer.
• The correct sentence is: She had continued her classes and was somehow maintaining acceptable grades.
• The meaning of the term 'acceptable' can be agreed upon; appropriate.
• - For instance, the election systems must be acceptable to the public.