Question

water moves by capillary action through soil from moist areas to dry areas. which property of water is most responsible for this capillary action?
water is a polar molecule.
water contains an oxygen atom.
water has a high surface tension.
water has a high specific heat.

Explanation:

Capillary action occurs due to the combination of adhesion (attraction between water molecules and the soil surface) and cohesion (attraction between water molecules). Water is a polar molecule ($H_2O$, with a partial positive charge on hydrogen and partial negative charge on oxygen). This polarity leads to strong hydrogen - bonding between water molecules (cohesion) and also allows water molecules to adhere to polar soil surfaces. High specific heat is related to temperature regulation of water, high surface tension is related to phenomena like water striders walking on water, and the fact that water contains an oxygen atom is a basic composition fact but not directly responsible for capillary action.

Answer:

Water is a polar molecule.