Mix up with singular and plural answers
The French/English answers are backwards:the singular translation is listed as the plural answer and vice-versa. "The grapes are red" shows "Le raisin est rouge.", and "The grape is red." shows the plural answer.
In short: 'grape' does not mean 'raisin'. It is more subtle than that. It means 'grain de raisin'. So, most of the time 'raisin' (singular) will be translated into 'grapes' (plural).