The vector a = αi + 2j + βk lies in the plane of the vector b = i + j and vector c = j + k and bisects the angle between vector b and vector c. Then which one of the following gives possible values of a and β?
(a) α = 1, β = 1
(b) α = 2, β = 2
(c) α = 1, β = 2
(d) α = 2, β = 1
