Detailed understanding of the cellular basis of signaling in the nervous system has lead to good und

I need help answering these last four questions. I've answered 44 questions out of 48 and I can't figure out these last four so can someone please HELP me??

QUESTIONS

1.) detailed understanding of the cellular basis of signaling in the nervous system has lead to good understanding of consciousness, intelligence, and emotions.
                                                    A. true
                                                    B. false

2.) which of the following is NOT a known drug effect on synaptic function.
                                      A. interfere with neurotransmitter synthesis
                                      B. alter the rate of neurotransmitter release
                                      C. prevent neurotransmitter inactivation
                                      D. prevent neurotransmitter binding to receptors
                                      E. change the type of neurotransmitter found in the synaptic vesicle

3.) caffeine and related stimulants exert their effects by
                                 A. mimicking a specific neurotransmitter
                                 B. inhibiting a specific neurotransmitter
                                 C. mimicking a specific neuromodulator
                                 D. inhibiting a specific neuromodulator

4.) a molecule that blocks substance P from binding to its receptor would
                                          A. stimulate a painful sensation
                                          B. inhibit the perception of pain
                                          C. alter the perception of hot and cold stimuli
                                          D. interfere with transduction from chemoreceptors