An ideal, incompressible fluid flows through a horizontal pipe. At section 1, the pipe has a circular cross-section with diameter \(D\) and the fluid flows with speed \(v_1\). The pipe then tapers to section 2, which has a circular cross-section with diameter \(\dfrac{D}{2}\) and the fluid flows with speed \(v_2\). Which of the following correctly compares \(v_2\) to \(v_1\) and provides a valid justification?