For the reaction \[{{H}_{2}}\left( g \right)+B{{r}_{2}}\left( g \right)\to 2HBr\left( g \right),\] the experimental data suggest, rate\[=k[{{H}_{2}}]{{[B{{r}_{2}}]}^{1/2}}\]. The molecularity and order of the reaction are respectively

• A. \[2,\frac{3}{2}\]                        
• B. \[\frac{3}{2},\frac{3}{2}\]
• C. 1,1                               
• D. \[1,\frac{1}{2}\]