Final answer:
The equation -9d - √(-d) - 8 = 0 has no real solution because it involves taking the square root of a negative number, which is not defined in the set of real numbers.
Step-by-step explanation:
The student is asking to solve the equation -9d - √(-d) - 8 = 0 for the variable d. This equation involves a square root and a variable, indicating the need to find a number that, when substituted for d, will make the equation true. However, there's an issue with the equation as it includes the square root of a negative number, √(-d), which is not defined within the realm of real numbers as square roots of negative numbers are imaginary. Therefore, without even trying to isolate the variable d, we can conclude that there is no real solution to this equation, and the answer is D) ∅.