Final answer:
The value of c that makes x² - 8x + c a perfect square trinomial is 16.
Step-by-step explanation:
To make the trinomial x² - 8x + c a perfect square trinomial, we need to find the value of c. A perfect square trinomial can be factored into the form (x - a)², where a is a constant.
We can find the constant c by taking half of the coefficient of x, squaring it, and subtracting it from c. In this case, the coefficient of x is -8. Half of -8 is -4, and (-4)² is 16.
Therefore, the value of c that makes x² - 8x + c a perfect square trinomial is B) 16.