The formula for speed is:
[tex] v = \frac{x}{t} [/tex]
Where x is the 'rise' and t is the 'run'. If x is growing faster for every interval of t, it means that the speed is increasing. The only way this can happen is if x has exponential, cubic or quadratic growth.
Because you need constant speed, your answer is the line with the constant slope, or Object A.
