Energy= 2381 joules
heat= Mass(kg) *change in temperature(K) * Cp
2381=0.155*(15)*Cp
Cp=1024 J/kg K
Based on the information I would assume B, 73 degrees...
It shouldn't be A, 4 minutes on the burner should increase the temperature.
If it were D, it would be beyond boiling, and water takes a decent amount of energy to heat, D should be all vapor.
Same logic for C, it's basically almost boiling.
I would say 73 degrees seems most reasonable for 4 minutes.
Acetic Acid has two C atoms, four H atoms, and two O atoms, so the molecular formula is C2H4O2.