Lady Macbeth's intent can be interpreted in multiple ways, but based on the options provided, the most fitting interpretation would be:
D. She does not consider the murder to be a subject worthy of considerable thought.
This interpretation aligns with her character and her desire to push Macbeth to take decisive action, demonstrating her belief that dwelling on their crime could lead to weakness and madness, which would impede their ambition. Lady Macbeth often urges her husband to suppress any guilt or remorse and instead focus on their path to power.