ANSWER
Graph (B)
Step-by-step explanation
As we can see in the graph of acceleration vs. time, the acceleration of the body is constant and negative. Mathematically, the acceleration is the derivative of the velocity. This means that the acceleration of a body represents the slope of the velocity-time graph.
Hence, since the acceleration is negative and constant, the graph of the velocity is a straight line with a negative slope. In other words, the graph representing this body's velocity is graph (B).