What volume of hydrogen gas at 273K and 1atm pressure will be consumed in obtaining 21.6g of element boron (at.mass=0.8) from the reduction of boron trichloride with hydrogen ?

Question

$(a)\;44.8L\qquad(b)\;22.4L\qquad(c)\;89.6L\qquad(d)\;67.2L$