Final answer:
The correct simplification of 2d-5 is option a) 2d-65.
Step-by-step explanation:
The correct simplification of 2d-5 is a) 2d-65. To simplify the expression, we rewrite it without parentheses and combine like terms. The term -5 remains unchanged as it doesn't have a similar term to combine with.
Therefore, the simplified expression is 2d-5.