Final answer:
Guy de Maupassant aims to evoke a mood of melancholy in "Was it a Dream?", focusing on themes of loss and existential despair.
Step-by-step explanation:
In "Was it a Dream?" by Guy de Maupassant, the mood that the author hopes to evoke in the reader is most closely associated with melancholy. Through narrative elements detailing the spectral and somber, Maupassant artfully cultivates an atmosphere laden with sadness and reflection on mortality. The story traverses through themes of loss, mourning, and existential despair, leaving readers enveloped in a poignant and contemplative mood.