A vaccine for SARS-CoV-2 in clinical trials generated neutralizing IgG antibodies, antigen-specific CD8 cytotoxic T effector cells, and memory B cells. Select the correct statement about the SARS-CoV-2 vaccine and the clinical trial results. a. Peptides generated from the SARS-CoV-2 vaccine were presented in MHC class II molecules. b. Dendritic cells did not need to be activated by the vaccine to produce neutralizing antibodies or CD8 effector cells. c. CD4 T cells were unlikely to have been activated by the vaccine. d. Neutralizing antibodies provide protection by activating complement. e. The vaccine is an example of passive immunity that will generate long-lasting protection.