On mixing `15.0` ml of ethyl alcohol of density `0.792"g ml"^(-1)` with 15 ml of pure water at `4^(@)C`, the resulting solution is found to have a density of `0.924"g ml"^(-1)`. The percentage contraction in volume is :
A. `8%`
B. `2%`
C. `3%`
D. `4%`