Question

to die of hanging at the bottom of a river!—the idea seemed to him ludicrous.
source: an occurrence at owl creek bridge
in the sentence above, ludicrous has the same or almost the same meaning as:
cruel
absurd
plausible
terrifying

Explanation:

"ludicrous" means so foolish, unreasonable, or out - of - place as to be amusing or ridiculous. "absurd" means wildly unreasonable, illogical, or inappropriate. They are similar in meaning. "cruel" means causing pain or suffering, "plausible" means seemingly reasonable or probable, and "terrifying" means causing extreme fear.

Answer:

B. absurd