500 mL, `0.2"M NA"_(2)SO_(4)` solution is mixed with 100 mL, `17.1%(w//v)Al_(2)(SO_(4))_(3)` solution and resulting solution is diluted to 5 times. Find the molarity of `SO_(4)^(-2)` ions in the final solution.
[Atomic mass of Al = 27, S = 32, Na = 23]
A. `(1)/(12)M`
B. `(5)/(12)M`
C. `(7)/(5)M`
D. `(12)/(5)M`