A 28-year-old woman who is 10 weeks pregnant presents to the obstetrics clinic for prenatal care. She has a history of treatment for syphilis 7 years previously. The results of serologic tests for syphilis are as follows: nontreponemal test, RPR, nonreactive; treponemal test (TP-PA), reactive. Which of the following statements is most correct?

A. The baby is at high risk for congenital syphilis
B. The mother’s previous treatment for syphilis was effective.
C. The mother needs to be treated again for syphilis
D. The mother needs a lumbar puncture and a VDRL test of her CSF for neurosyphilis