The correct answer is C. Both (i) and (iii).
Bearing stiffeners are provided at the supports and the point of application of concentrated loads to reduce the local stresses and bending moments in the beam.
At the supports, the bearing stiffeners are provided to resist the bearing stresses developed due to the reaction forces from the supports. The bearing stresses are concentrated at the supports and can cause local buckling of the beam. The bearing stiffeners help to distribute the bearing stresses over a larger area and prevent local buckling.
At the point of application of concentrated loads, the bearing stiffeners are provided to resist the bending moments developed due to the concentrated loads. The bending moments are concentrated at the point of application of the concentrated loads and can cause local buckling of the beam. The bearing stiffeners help to distribute the bending moments over a larger area and prevent local buckling.