Answer:
C. Time since the person starts walking is the input.
D. t represents the input.
Step-by-step explanation:
The distance a person walks, d, in kilometers, is a function of time, t, in minutes, since the walk begins.
So, we can write d = f(t)
If the person is moving with constant speed, then the above function will be linear.
Now the true statements are
C. Time since the person starts walking is the input.
D. t represents the input.
All the other statements are false. (Answer)