Consider these four line graphs representing speed in meters/second, where each X-axis is labelled in seconds and each Y-axis is labelled in meters.

What do the four graphs have in common?
Responses
A They all indicate a constant speed.They all indicate a constant speed.
B All four graphs have nothing in common.All four graphs have nothing in common.
C They all represent the same speed in m/s.They all represent the same speed in m/s.
D They all indicate an increase in speed.