The correct answer is option 'C' - Capillary Water.

Explanation:
Surface tension is the property of a liquid that allows it to resist an external force, caused by the cohesive forces between its molecules. This property is responsible for the curved shape of liquid droplets and the formation of meniscus in a tube.

Field capacity is the maximum amount of water that can be retained in the soil after excess water has drained away and the rate of downward movement has decreased significantly. It represents the water content at which the soil is adequately moist for plant roots to extract water.

The water in the soil is divided into several categories based on the forces acting on it. One of these categories is capillary water, which is the water held in the soil against the force of gravity by capillary action.

Capillary action is the ability of a liquid to flow in narrow spaces against the force of gravity. In the soil, the small spaces between soil particles create capillary tubes, which allow water to be drawn upward.

Capillary water is held in the soil by capillary forces, which are stronger than the force of gravity. This water is available to plants for their growth and is essential for their survival.

Other categories of water in the soil include:
a) Hygroscopic Water: This is the water that is held tightly by the soil particles and is not available to plants. It is strongly bound to the soil particles and is not easily extractable.
b) Gravity Water: This is the water that drains freely through the soil under the force of gravity. It is not held by the soil particles and is not available to plants.
d) Residue Water: This is the water that remains in the soil after drainage and is held in the larger pores. It is not easily available to plants as it is held too tightly by the soil particles.

In summary, based on surface tension, capillary water is the part of field capacity water that is held in the soil against the force of gravity by capillary action. It is the water that is available to plants for their growth and is essential for their survival.