Missy spencer was given penicillin for tonsillitis. she developed a severe life-threatening allergic (hypersensitivity) reaction to the penicillin. her medical file records this reaction as a(n):

The reaction of which Missy has experience that is a severe and life threatening allergic reaction due to penicillin is anaphylactic reaction, it could be classified as the a serious and life threatening in terms of having allergic reaction for if not treated immediately, it could cause death to the individual who has experience this reaction. This could be triggered from either medications, food in which an individual has consumed and insect stings such as from bees. Missy’s allergic reaction must have triggered because of the penicillin that she has consumed where in, she does not know that she is allergic to the medication, having her to experience a life threatening allergic reaction to the penicillin.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.