Please answer question 14question and explain the solution

14. A wave traveling on a string is given by y(x, t) = A cos(12.6t 4x). Which of the following correctly describes the wave? A. It's traveling in the +y direction with wavelength 6.3 m B. It's traveling in the +9: direction with frequency 2 Hz D. It's traveling in the x direction with frequency 1 Hz E. It's traveling in y direction with wavelength 1.6 m