Singer Argues That If We Are Prepared to Perform Painful

Singer argues that if we are prepared to perform painful experiments on nonhumans, the moral principle of equal consideration of interests requires that we be equally prepared to perform such experiments on

A) any beings with capacities for suffering similar to those of the nonhumans in question.
B) adult humans.
C) humans who have been found guilty of harming others.
D) any other nonhumans with similar capacities for suffering.