tissue swelling in response to envenomation

Inspired by this collection of photos of dogs who thought it was a good idea to eat bees.

Why is swelling a common response to insect stings? Is this:

A) an evolved response on the part of the victim that somehow helps it cope with the venom,

or

B) an evolved property of the venom that helps make a sting more unpleasant, thereby helping the stinging insect,

or

C) a side effect of envenomation that isn’t particularly helpful to either party?

Its an immune response. http://biology.stackexchange.com/questions/17032/why-do-bee-stings-cause-swelling

Google is your friend.

angioedema.