A 20.0-milliliter sample of 0.200 M K₂CO₃ solution is added to 30.0 milliliters of 0.400 M Ba(NO₃)₂ solution.
Barium carbonate precipitates.

The concentration of barium ion, Ba₂⁺, in solution after reaction is:

(A) 0.150 M
(B) 0.160 M
(C) 0.200 M
(D) 0.240 M
(E) 0.267 M