Why Are Antibiotics from the Tetracycline Drug Group Seldom Prescribed

Why are antibiotics from the tetracycline drug group seldom prescribed during pregnancy?

A) Although the mother may have an infection,the fetus does not;giving these drugs to the mother would expose the fetus to unnecessary drugs.
B) The pregnant woman does not metabolize tetracycline to its active form and excessively high doses are needed for an intended action.
C) These drugs reduce the thickness of the enamel in developing teeth,so the infant would have darkly stained teeth.
D) The fetal liver is too immature to inactivate these drugs and eliminate them;they increase the risk for severe birth defects.