Answer:
is changing in direction, but constant in magnitude
Explanation:
This question is a bit tricky since the velocity of the satellite is changing, but the speed is constant.
Speed is simply a measure of how fast you are going. It doesn't matter where you're going, just how quickly.
Velocity, on the other hand, does care about which direction you're going. For example, it could be then when you travel right, your velocity is positive, and when you travel left, your velocity is negative. This is the similar for a 2D shape like a circular orbit
Since we know velocity is changing, there must be acceleration which changes that velocity (since acceleration is the change in velocity: going from 0 to 60 mph, for example)
Thus, with a non-zero net acceleration, we know that there must be a force that is changing in direction, but constant in magnitude (since the orbit is a circle, and always attracted to the center of the Earth at equal distance).