A sunflower moving towards the sun shows

The correct answer is: Movement

Plants are living beings like us. They shows different kinds of movement. Some are internal and some are external to complete their life process.
The movement of sunflower here is in response to the external stimulus, sunlight, for performing photosynthesis. Sunlight act as external stimulus. This phenomenon known as heliotropism which states movement of plants towards the sun to gather more sunlight to perform photosynthesis.