Parents of a 6-Month-Old Child,who Has Just Been Diagnosed with Iron

Parents of a 6-month-old child,who has just been diagnosed with iron deficiency anemia,ask why it was not diagnosed earlier.What would be the best response by the nurse?

A) "Are you sure your child has iron deficiency anemia?"
B) "This happens when the maternal stores of iron are depleted at about 6 months."
C) "This anemia is caused by blood loss."
D) "The child may not have had it for a long time."