Appendix D - Graphing Techniques - Exercises - Page 448: 12f

Graph "A" is the correct sketching.

For $y = |-x|,$ when $x=2, y=2, x=0, y=0$ and $x=-2, y=2$ The curve passes through $(2,2), (0,0)$ and $(-2,2)$. Since the graph of $y=|-x|$ is the same as the graph of $y=|x|$ and $y=|-x|$ can be seen as the reflection of $y=|x|$ across the y-axis as well , graph "A" is the correct sketching.