A simple harmonic progressive wave is represented by the equation:
`y=8 sin 2 pi (0.1x-2t)`
Where x and y are in cm and t is in seconds. At any instant the phase difference between two particles separated by 2.0 cm in the x-direction is:
| A. |
`18^o` |
| B. |
`36^o` |
| C. |
`54^o` |
| D. |
`72^o` |
 |