This is College Physics Answers with Shaun Dychko. The super position principle says that if you have two waves in the same place, the result will have an amplitude equal to the sum of the amplitudes of each of the waves. So, you have one wave with an amplitude A and another wave with an amplitude of 3A. And so, their sum will be of amplitude 4A. And, there's no interference effects to be concerned with here because we're talking about the central fringe. And so, the answer here is B.