A Newborn Is Being Evaluated Due to Low Growth Perecentile

A newborn is being evaluated due to low growth perecentile. the patient is delivered via elective cesarean section at 38 weeks gestation. APGAR scores are 8 and 9 at 1 and 5 minutes, respectively.  Head circumference measures <10th percentile, and the placenta has numerous calcifications.  Serology is consistent with congenital toxoplasmosis.  As part of treatment, he is prescribed a combination of pyrimethamine and sulfadiazine.  A medical student in the round has asked about the reason to use two different medications to treat this patient?

A) Broader spectrum of coverage
B) Enhanced intracellular drug penetration
C) Enzymatic inhibition of an inactivating enzyme
D) Reduced urinary excretion of active metabolites
E) Synergistic reduction of DNA synthesis