Explanation:

The correct option is 2nd i.e. Capillary action.

• The oil in the wick of an oil lamp rises up due to capillary action. This effect is due to surface tension of liquids. The wick here acts as a capillary tube.

• Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity.

• The effect can be seen in the drawing up of liquids between the hairs of a paint- brush, in a thin tube, in porous materials such as paper, in some non-porous materials such as liquefied carbon fiber, or in a cell.

• It occurs because of inter-molecular attractive forces between the liquid and solid surrounding surfaces.