Answer: c. NH3
Explanation:
Ammonia(NH3) has the highest boiling point at -33.34 °C while Methane (CH4) has a boiling point of -161.6 °C and Hydrogen sulfide (SH2) has a boiling point of -60 °C.
This is because Ammonia can form strong hydrogen bonds but which makes it harder to boil than the others.
