Calcium lactate is a salt of weak organic acid and strong base represented as `Ca(LaC)_(2).` A saturated solution of `Ca(LaC)_(2)` contains 0.6 mole in 2 litre solution. pOH of solution is 5.60. If `90%` dissociation of the salt takes place then what is `pK_(a)` of lactic acid?
A. `2.8-"log"(0.54)`
B. `2.8+"log"(0.54)`
C. `2.8+"log"(0.27)`
D. `2.8-"log"(0.27)`