Bastion means a stronghold, fortified position, or something serving as a defense, literally a projecting part of a fortification. Figuratively, it's a bastion of freedom or a bastion of conservatism. Option A ('utter complaining indistinctly') is 'mutter', B ('foul-smelling') is 'malodorous', and C ('shining brightly') is 'dazzling' or 'effulgent'.