The Next Step in Investigating a Positive Direct Antiglobulin Test

The next step in investigating a positive direct antiglobulin test using polyspecific antihuman globulin reagent should be to:

A) repeat the direct antiglobulin test using warm saline.
B) perform an eluate.
C) add IgG-sensitized red cells to verify positive reaction.
D) repeat the direct antiglobulin test using monospecific anti-IgG and anti-C3 reagents.