The correct answer is C, hypocrisy. This work of Mark Twain's is actually a fictionalized version of his own wartime experiences. He is trying to tell us that there is nothing glorious about war, that there is only death and suffering. It cannot be glorious when you have to kill somebody, or somebody will kill you. That's the irony and hypocrisy that Twain was trying to convey in this work.
A serpent and an elephant. It was a town of machinery and tall chimneys, out of which interminable [unending] serpents of smoke trailed themselves for ever and ever, and never got uncoiled. It had a black canal in it, and a river that ran purple with ill-smelling dye, and vast piles of building full of windows where there was a rattling and a trembling all day long, and where the piston of the steam-engine worked monotonously up and down, like the head of an elephant in a state of melancholy madness.
The answers are b, d, and e