B. Histones is the correct answer.
I believe he is looking for an allele
An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosomes. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.
In the given case, Adeline is probably to get scared and shocked regarding menarche as the culture of her time did not assist in educating young women about menarche.
Menarche refers to the initiation of the menstrual cycle, or first menstrual bleeding, in females. From both the medical and social point of view, it is usually regarded as the principal incident of female puberty, as it indicates the probability of fertility.
Answer: C). prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm
Explanation: In the epinephrine pathway, binding of epinephrine to its receptor triggers a conformational change in the receptor and the interaction of the receptor with its associated Gs protein. This interaction causes the replacement of GDP bound to Gs protein with GTP thus activating the Gs protein. The activation of the Gs protein causes the alpha subunit of the Gs protein to dissociate and move to adenylyl cyclase, another membrane protein in the pathway. The association of the alpha subunit of the Gs protein with adenylyl cyclase activates adenylyl cyclase which in turn catalyzes the synthesis of cyclic AMP (cAMP) a second messenger. cAMP is quickly degraded to 5'-AMP by an enzyme phosphodiesterase. Inhibition of the activity of phosphodiesterase will increase the half life and the cytoplasmic level of cAMP thus potentiating the action of epinephrine.
"it reacts strongly when the drug is absent, a reaction known as withdrawal"