I believe the answer is C but I havent seen this stuff in a while.
the food supply in Elizabethan England
The entire paragraph is about the food supply in Elizabethan England. It describes how food was valuable because it was not always easy to acquire. Travel was more difficult in Elizabethan England than in present day so the food supply was limited to what was available close by. Food options also varied by season. Some due to when certain fruits and vegetables were ale to grow and others due to when the food could be carried to different markets.
The possessive phrase will be: The children's toys.