A.)rocky areas unsuitable for planting crops
B.)lacking any rivers for transportation
C.)Atlantic Ocean coastline full of bays and harbors
D.)long, hot summers and mild winters
Yes here in the south we have really really rocky areas but in the end, we still plant because we level things out and make it suitable for planting... that's why A is out.
There are a lot of rivers and a lot of transportation is used on them. That's why B is out.
The Atlantic Ocean coastline is full of bays but ain't it also for the north..? That's why C is out.
Our summers are scorching and they last from around the second week of May up until September. Our winters aren't too bad typically. That's why I think D is the answer.
I hope this helps you :)