A mother who received no prenatal care tests positive for syphilis antibodies. At birth, her baby ...

A mother who received no prenatal care tests positive for syphilis antibodies. At birth, her baby
  girl also tests positive for syphilis antibodies. What should be done?
 
  A) The infant should not be treated since the positive syphilis test is probably due to the
  mother's IgG syphilis antibodies crossing the placenta.
  B) The infant should be treated if IgM syphilis antibodies can be demonstrated in her
  mother's serum.
  C) The infant definitely has syphilis and should be treated for syphilis as well as the mother.
  D) The infant should be treated if IgM syphilis antibodies can be demonstrated in her serum.