The correct answer is B. Irony
Step-by-step explanation:
The irony is a poetic device in which there is an incongruence between the expectations in a situation and the reality or real outcome. In the case of the excerpt poem "The Rime of the Ancient Mariner" irony is the main poetic device used, because the author explains the mariner is surrounded by water and despite this, there is no water for him to drink "Water, water, everywhere, Nor any drop to drink" which show an incongruence between what is expected and the reality or between a lot of water but not of this being appropriate to drink. Thus, the poetic device these lines illustrate is Irony.