H₂(g) +I₂(g)→2HI(g) the rate of disappearance of H₂ is 1.0 ×10⁻⁴ mol L⁻¹ s⁻¹. The rate of appearance of HI will be:

A. 1.0 ×10⁻⁴ mol L⁻¹ s⁻¹
B. 2.0 ×10⁻⁴mol L⁻¹ s⁻¹
C. 4.0 × 10⁻⁴ mol L⁻¹ s⁻¹
D. 0.50 ×10⁻⁴ mol L⁻¹ s⁻¹