Answer:
:O Fr? Bet let me go get them lol
The answer is A because it cannot be B because that is ethylene and not D because it needs a subscript of 2 since it is a diatomic and it is no C because it is not carbon dioxide its oxygen
B Very Acidic llllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
5 times dilution
0.780M x 1/5 = 0.156M
Hope this help.