Answer:
the first one, 64(-1/2)^(n-1)
Explanation:
To go from one number to the next, we first start with 64, so everything is multiplied by that. Next, 64 turns into -32, and (-32)/64 = -1/2. Similarly, 16/-32 is -1/2, and -8/16 is -1/2 as well. Therefore, we have to multiply each number by -1/2 a number of times. For example, to get from 64 to 16, we have to multiply 64 by negative one half 2 times. The only option with -1/2 in the multiplier is the first one, making that our answer