Answer:
B. -6+8d-2c C. -2c+8d-6
Explanation:
In order to determine which expressions are equivalent to 
 you need to set the expression equal to the options available.
 you need to set the expression equal to the options available. 
For example, to check if A. works:

You want to repeat the process as shown above with the rest of the options. If both sides equal to each other, once solved, that means that will be the answer.