A 27-year-old G2 P1 presents with a history of fatigue, night sweats, dysphagia, and shortness of breath. Further evaluation reveals a large mediastinal tumor, which is determined to be a large B-cell lymphoma. Treatment with CHOP (Cyclophosphamide, Doxorubicin, Vincristine, Prednisone) in the antenatal period and CHOP + rituximab in the postnatal period is planned. Which of the following anticancer drugs is considered highly teratogenic and should be generally avoided?

A) Doxorubicin
B) Methotrexate
C) Rituximab
D) Tretinoin