Calculate the limit lim_{x \to -3^-} f(x) for f(x) = \begin{cases} √{-2-x} + 2, & \text{if } x < -3 \\ 2, & \text{if } x = -3 \\ 4x + 15, & \text{if } x > -3 \end{cases}. Enter DNE if the limit does not exist.
a) 2
b) 5
c) DNE
d) 17