Answer :
The incorrect possessive is in D: the sheeps' pen.
Sheeps is not a word: the plural of sheep is just the same: sheep. So the possesive of this should be sheep's. Pronunciation would be the same as sheeps', but the spelling is different.
Sheeps is not a word: the plural of sheep is just the same: sheep. So the possesive of this should be sheep's. Pronunciation would be the same as sheeps', but the spelling is different.