Describe uniform straight-line rectilinear motion and uniformly accelerated motion through qualitative descriptions.

a) Uniform straight-line rectilinear motion involves constant speed in a straight line, while uniformly accelerated motion involves changing speed over time.
b) Uniform straight-line rectilinear motion involves changing speed over time, while uniformly accelerated motion involves constant speed in a straight line.
c) Both uniform straight-line rectilinear motion and uniformly accelerated motion involve constant speed in a straight line.
d) Both uniform straight-line rectilinear motion and uniformly accelerated motion involve changing speed over time.