What volume of 0.1125 M K₂Cr₂O₇ would be required to oxidize 68.16 mL of 0.3006 M Na2SO3 in acidic solution? The products include Cr³⁺ and SO₄²⁻ ions.
a) 45.00 mL
b) 90.00 mL
c) 135.00 mL
d) 180.00 mL