Why Does Steinbock Discuss Singer's Argument in This Paper

Why does Steinbock discuss Singer's argument in this paper?

A) Steinbock uses Singer's argument to explain why animal cruelty is wrong.
B) Steinbock uses Singer's argument to explain why medical research using animals is wrong.
C) Steinbock argues that Singer is incorrect when he concludes that it is morally wrong to privilege humans' interests over those of nonhumans.
D) Steinbock argues that Singer is wrong when he claims that nonhuman animals have the capacity for suffering and enjoyment.