A is qualitatively correct. The centripetal acceleration points along the string. At this point there is also a tangential acceleration, in the direction of motion. The vector sum of these is consistent with the direction of the acceleration shown.
B is incorrect. At its lowest point the speed has a maximum, and so the rate of change of the speed is zero. There is no tangential component of acceleration which points along the string, and thus upwards
C is incorrect. The centripetal acceleration points along the string. At this point there is also a tangential acceleration, directed back along the path, reflecting the fact that the pendulum is slowing down.
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