Which choice has an incorrectly spelled word and the spelling rule that would correct it?
a) flatest; adding a suffix beginning with a vowel.

b)noticable; double the consonant when adding a suffix .

c)noticable; adding a suffix that begins with a vowel .

i think the answer is "c."but i'm not certain ; for the in advance .
d) flattest; doubling the consonant when adding a suffix.