<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A group of scientists is conducting an experiment on the human cells involved in the immune response. They genetically modify B cells so they do not express the cluster of differentiation 21 CD21 on their cell surfaces. The pathogenesis of which of the following organisms would most likely be affected by this genetic modification?? A: Epstein-Barr virus EBV, B: Measles virus, C: Human immunodeficiency virus HIV, D: Human papillomavirus, E: Parvovirus B19,  <response>: This question is asking about which pathogen would be most affected by genetically modifying B cells to not express CD21. CD21 is a receptor for Epstein-Barr virus EBV on B cells. EBV infects B cells by binding to CD21. So not expressing CD21 would prevent EBV from infecting B cells. The other pathogens listed use different receptors to infect cells.Therefore, Epstein-Barr virus would be most affected by the genetic modification to B cells.A: Epstein-Barr virus EBV 