The Use of Chemotherapy for Brain Tumors Is Complicated by the Fact

Multiple Choice

 The use of chemotherapy for brain tumors is complicated by the fact that

A) brain tumors do not respond to traditional chemotherapy.
B) chemotherapy causes too much damage to neurons to be considered as a treatment for brain tumors.
C) many substances used in traditional chemotherapy do not cross the blood-brain barrier.
D) substances used in traditional chemotherapy mimic the actions of naturally occurring neurotransmitters.