A transverse progressive wave on a stretched string has a velocity of \[10\,m{{s}^{-1}}\] and a frequency of 100 Hz. The phase difference between two particles of the string which are 2.5 cm apart will be [MP PMT 1994]

• A.            \[\frac{\pi }{8}\]                 
• B.            \[\frac{\pi }{4}\]
• C.            \[\frac{3\pi }{8}\]               
• D.            \[\frac{\pi }{2}\]