The reaction of hydrogen and iodine monochloride is given as:
H₂(g)+2ICl(g)→2HCl(g)+I₂(g)

This reaction is of first order with respect to H₂(g) and ICl(g), following mechanisms were proposed :
Mechanism A : H₂(g)+2ICl(g)→2HCl(g)+I₂(g)
Mechanism B : H₂(g)+ICl(g)→HCl(g)+HI(g), slow
HI(g)+ICl(g)→HCl(g)+I₂(g),fast

Which of the above mechanism(s) can be consistent with the given information about the reaction?