In Britain, Thousands Have Protested for and Against Scientific Animal

In Britain, thousands have protested for and against scientific animal testing, with each side trying to make its case in the streets and in the media. What plausible utilitarian argument could scientists and others make in favor of the testing?

A) Animal testing produces greater net benefits to society than not testing. The pain suffered by test animals is more than offset by the cures and treatments that the tests help develop.
B) Animals are to be used for the benefit of humankind, so whatever suffering the test animals endure is permissible.
C) Animals and humans have equal inherent value. Because humans should not be kept in cages, experimented on, and otherwise abused, neither should animals.
D) Humans have infinite moral worth, but animals have little or none. So, it is permissible to use animals in the service of humans, just as it is permissible to use a hammer to build a house.