The Reaction Between Selenous Acid and the Iodide Ion in Acid

The reaction between selenous acid and the iodide ion in acid solution is
H₂SeO₃(aq) + 6I^-(aq) + 4H⁺(aq) → Se(s) + 2I₃^-(aq) + 3H₂O(l)
The data in the following table were measured at 0°C.
Experiment
[H₂SeO₃]₀ (M)
[H⁺]₀ (M)
[I^-]₀ (M)
Initial Rate [mol/(L ∙ s) ]
1
1) 00 × 10^-4
2) 00 × 10^-2
3) 00 × 10^-2
5) 30 × 10^-7
2
2) 00 × 10^-4
2) 00 × 10^-2
3) 00 × 10^-2
1) 06 × 10^-6
3
3) 00 × 10^-4
4) 00 × 10^-2
3) 00 × 10^-2
6) 36 × 10^-6
4
3) 00 × 10^-4
8) 00 × 10^-2
3) 00 × 10^-2
2) 54 × 10^-5
5
3) 00 × 10^-4
8) 00 × 10^-2
6) 00 × 10^-2
2) 04 × 10^-4
6
2) 00 × 10^-4
2) 00 × 10^-2
6) 00 × 10^-2
8) 48 × 10^-6
The overall order of this reaction is

A) 4.
B) 6.
C) 2.
D) 8.
E) 3.