Answer: Listeria
Explanation: I looked up "what food pathogen is dangerous to the placenta" and this food pathogen was the main answer. I also double-checked different articles and they all said the same thing.
Zidovudine the first antiretroviral drug, became availabale to treat HIV on febuary 4 i dont rember what year, hope that helps you out
I believe the asnwer would be 2 or 3.