The answer is b discharge
You would have used B. context clues. The reasoning for this is you have used other words in the sentence and around this word to help you figure the meaning.
Menacing= threatening
Interminable= Continuous or never-ending
Exuded=To give off a smell or attitude
Noxious=poisonous
Vast=huge
Monotonously= Repeating the same actions so that it becomes boring.
Melancholy= Deeply sad
Inhabited=Lived in or on