As the temperature is increased, the period of a pendulum a) Increases as its effective length increases even through its centre of mass still remains at the centre of the bob. b) decreases as its effective length increases even though its centre of mass still remains at the centre of the bob. c) Increases as its effective length increases due to shifting of centre of mass below the centre of the bob. d) decreases as its effective length remains same but the centre of mass shifts above the centre of the bob.