Why is no constant of integration added when computing displacement from $t_1$ to $t_2$ using a definite integral of velocity?

• A. Because the units of displacement prevent constants from appearing in antiderivatives
• B. Because definite integrals always equal zero when a constant is present
• C. Because velocity vectors cannot have constants of integration in two dimensions
• D. Because displacement is obtained by evaluating an antiderivative at the endpoints, so any constant cancels in final minus initial

Answer: (D)