Constant acceleration requires linear speed-time relationship

Steps:

• Calculate average acceleration for each time interval using a = Δv / Δt for bodies A, B, C, D.
• Check if acceleration values are equal across intervals for each body.
• Identify the body where acceleration varies between intervals.
• Confirm non-linearity in speed vs. time for that body.

Why A is correct:

• Acceleration is not constant if average a differs across intervals, violating the definition of constant acceleration (dv/dt = constant).

Why the others are wrong:

• B: Acceleration values are equal across all intervals, indicating constant acceleration.
• C: Speed increases linearly with time, so acceleration is constant.
• D: Consistent Δv per Δt shows uniform acceleration.

Final answer: A