Final answer:
The mood of 'Lamb to the Slaughter' is dark and moody, as highlighted by Roald Dahl's use of irony and characteristically dark humor. Therefore correct option is A
Step-by-step explanation:
The mood of the story Lamb to the Slaughter by Roald Dahl can best be described as dark and moody. This is evident through the story's plot twists, the irony of the situation, and Dahl's characteristically dark humor. The atmosphere of tension and malice is subtly created through details and descriptions that, on the surface, may seem mundane or ordinary, such as the preparing of dinner, but underneath, carry a sense of foreboding.