An Athlete Is in the Early Weeks of an Aerobic

An athlete is in the early weeks of an aerobic training program and develops a decrease in hemoglobin concentration not associated with undue fatigue.Which statement is true?​

A) Decreased hemoglobin concentrations are never a cause for concern.
B) The athlete has an iron deficiency.
C) ​The athlete is experiencing low blood volume.
D) ​Taking a vitamin mineral supplement is necessary to correct the issue.
E) ​The athlete probably has a condition called sports anemia.