Chapter 4 - Inverse, Exponential, and Logarithmic Functions - 4.3 Logarithmic Functions - 4.3 Exercises - Page 445: 51

Option B is the correct option.

Since the formula is $log_2$$\frac{1}{x}$ , the graph should be tending to - infinity at 0 and have the value 0 at x = 1. Only option B satisfies these conditions. Hence, the correct option is B.