While making chicken soup for his family one evening, Luis added the amount of salt the recipe called for. After tasting the soup, he decided the seasoning was correct. He then he let the chicken soup simmer for two hours to blend the flavors. But when he served the soup, it was too salty. What happened to the soup to make it so salty?
A. He added to much solvent
B. He added something else besides salt
C. Some of the chicken was saltier than the rest of it
D. Some water evaporated and concentrated the salt