1. The problem states: If $2^x = 18$, find $\log_2 18$. 2. Recall the definition of logarithm: If $a^x = b$, then $\log_a b = x$. 3. Given $2^x = 18$, by definition, $x = \log_2 18$. 4. Therefore, $\log_2 18 = x$. 5. To express $\log_2 18$ in terms of simpler logarithms, note that $18 = 2 \times 9 = 2 \times 3^2$. 6. Using logarithm properties: $$\log_2 18 = \log_2 (2 \times 3^2) = \log_2 2 + \log_2 3^2 = 1 + 2 \log_2 3.$$ 7. Hence, the answer is $1 + 2 \log_2 3$, which corresponds to option E.