If potatoes only grow in warm weather, why can we get them in the winter?

If you plant your potatoes in late August, while it is still hot, you may still have them in the cooler months after. Cool weather doesn't really harm potatoes, they can still grow then, it is only when it is frosty that potatoes die off. The foliage will die, but the potatoes will remain securely underground until you are ready to dig them out. Additionally, potatoes can be grown indoors so that you can always have them. 

Iam not sure but to me it with be a or dsorry if i was late! hope this ! : )if you really want me to find out the answer that is correct tell me and i will do more research but the a or d makes sense to me.