6 : 72 :: 8 : ?

Answer: Option B

The question is an analogy, which means we need to find a relationship between the first pair of numbers (6 and 72) and apply the same relationship to the second number (8) to find the missing number.

Let's figure out the relationship between 6 and 72.
We can see that 72 is the result of multiplying 6 by 12 (6 x 12 = 72).

Alternatively, consider the operation 6 * (6 + 6) = 6 * 12 = 72
Or it could be 6² + 6 * x = 72, where x is 6.

Now, let's apply the same relationship to 8:
Following the same logic 8 * 12 = 96.

Alternatively, consider the operation 8 * (8 + 4) = 8 * 12 = 96
Or it could be 8² + 8 * x = 64 + 32 = 96, where x is 4.

Therefore, the missing number is 96.

So the answer is: Option B: 96.