Identify the Statement That Is True of the Heme Group

Identify the statement that is true of the heme group of hemoglobin.

A) The heme group contains an iron ion in its Fe³⁺ oxidation state.
B) The porphyrin part of the heme group consists of four pyrrole rings.
C) The pyrrole rings are linked together to form a tetrahedral structure.
D) The iron ion in the heme group has eight coordination sites.