The equations of a travelling and stationary waves are \[{{y}_{1}}=a\sin (\omega t-kx)\] and\[{{y}_{2}}=a\sin \,kx\,cos\,\omega t\]. The phase differences between two points \[{{x}_{1}}=\frac{\pi }{4k\,}\,and\,{{x}_{2}}=\frac{4\pi }{3k}\] are \[{{\phi }_{1}}\] and \[{{\phi }_{2}}\] respectively for two waves, where k is the wave number. The ratio of \[{{\phi }_{1}}/{{\phi }_{2}}\] is

• A. 6/7                   
• B. 44271
• C. 12/13   
• D. 44543