Step 1: Use triangles
The region is two right triangles. Left: vertices $(0,1)$, $(0,-1)$, $(-1,-1)$ with legs 2 and 1, area 1.
Step 2: Right triangle
Vertices $(0,1)$, $(0,3)$, $(1,3)$ with legs 2 and 1, area 1. Total 2, option (A).
Final Answer:
The total area is 2 sq. units, option (A).
\[ \boxed{2} \]