A square conducting loop of side length \(L\) and resistance \(R\) lies in the plane of the page and moves with a constant velocity \(v\) in the \(+x\)-direction. A region of uniform magnetic field \(B_0\) directed into the page exists in the interval \(0 < x < L\), and a region of uniform magnetic field \(B_0\) directed out of the page exists in the interval \(L < x < 2L\). The magnetic field is zero everywhere else. Counterclockwise induced emf is defined as positive. Which of the following graphs best represents the induced emf \(\varepsilon\) in the loop as a function of the leading edge's position \(x\) from \(x = 0\) to \(x = 3L\)?