The correct answer is E. Sodium transport channel. 

Note the classic bug bites in the interweb spaces consistent with a diagnosis of scabies. Treatment of scabies in this population (ie, pregnant women) should involve permethrin, which works by disabling the sodium channels of arthropods, leading to their paralysis.

Acetylcholinesterase inhibition is the action of malathion, metalloproteinase inhibition is the action of abametapir, fumarate reductase inhibition is the action of thiobendazole, and chloride ion channel inhibition is the action of ivermectin. Although ivermectin is likely safe, there are limited data on its use in pregnant women compared with permethrin, which is the treatment of choice.

References:

Patel VM, Lambert WC, Schwartz RA. Safety of Topical Medications for Scabies and Lice in Pregnancy. Indian J Dermatol. 2016;61(6):583-587. doi:10.4103/0019-5154.193659