Why Does Singer Discuss Bentham's and Sidgwick's Notions of Equality

Multiple Choice

Why does Singer discuss Bentham's and Sidgwick's notions of equality in this paper?

A) Singer considers their notions as providing objections to his claim.
B) Singer considers their notions as helpful in understanding what the principle of equality means.
C) Singer argues against their notions of equality because racism and sexism were rampant in the historical periods in which they lived.
D) Singer considers them examples of healthy vegetarians.