I believe that the answer is
<span>B.attempts to explain observations of the natural world</span>
Capsid I believe, I hope that helps!
Mutations can affect an organism by changing its physical characteristics (or phenotype) or it can impact the way DNA codes the genetic information (genotype). When mutations occur they can cause termination (death) of an organism or they can be partially lethal.
Activated cytotoxic cells (t lymphocytes) flags cells for destruction by macrophages. Ctotoxic t cells are the most important cells in the adaptive immunity, since they are required for almost all adaptive immune responses. They help activate B cells to secrete abtibodies and macrophages to destroy ingested microbes and also activate cytotoxic t cells to kill infected target cells.