Explanation

Since x varies inversely with y, we can write the equation:

x = k/y

where k is a constant.

Given that x = 4 when y = 16, we can find the value of k:

4 = k/16

k = 64

Now, we can find the value of x when y = 8:

x = 64/8

x = 8

So, the correct answer is: 8