11. A small air bubble is at the inner surface of the bottom of a beaker filled with cold water. Now water of the beaker is heated. The size of bubble increases. The reason for this may be

(a)  Increase in the saturated vapour pressure of water

(b)  Root mean square velocity of air molecules inside the bubble increases

(c)   Decrease in surface tension of water

(d)  All of the above

Ans. d

(11)