Which type of  movement is shown by the roots of plants towards soil ? 

Geotropism

The correct answer is Option (3) – Geotropism

Plants show tropism in response to other stimuli as well. The roots of a plant always grow downwards while the shoots usually grow upwards and away from the earth.

This upward and downward growth of shoots and roots, respectively, in response to the pull of earth or gravity is, obviously, geotropism .

Hydrotropism is the response of roots towards the water concentration.

Chemotropism is the response of plant parts in the direction of the chemical stimulus. One example of chemotropism is the growth of pollen tubes towards ovules.