[单选题]
Light of wavelength 550 nm in ;z2a.i* eflj+ 4onbkkd ;)iny air is found to travel agnm-o,b v 0p :2l opi;kxnc5m caw7:t7t $1.96 \times 10^8 \; m/s$ in a certain liquid. Determine the frequency of the light in the liquid.
A. $5.5 \times 10^{14} \; Hz$
B. $3.6 \times 10^{14} \; Hz$
C. $5.5 \times 10^{5} \; Hz$
D. $3.6 \times 10^{5} \; Hz$