If acceleration is constant and negative, velocity is what?

When acceleration is constant and negative, it indicates that the object is experiencing a uniform decrease in its velocity over time. Since acceleration is defined as the rate of change of velocity, a negative acceleration means that the velocity of the object is reducing consistently.

If the initial velocity of the object is positive, the negative acceleration will continuously subtract from that velocity, leading to a decrement in speed. This process continues until the velocity could reach zero, and if the negative acceleration persists, the velocity may turn negative, suggesting that the object is moving in the opposite direction.

In the context of the choices, since the question is focused on the behavior of velocity under conditions of constant negative acceleration, the option that accurately represents this relationship is that velocity is decreasing. Thus, the conclusion that velocity is decreasing aligns perfectly with the scenario described.