To which of the following directional stimulus roots of a plant do not respond?

When the leaves of a Mimosa pudica plant are touched with a finger, they fold up quickly. This is an example of:

Dandelion flowers open the petals in bright light during the daytime but close the petals in dark at night. This response of dandelion flowers to light is called:

One of the following is not caused by the growth related movement of the concerned plant part. This is:

The bending of the root of a plant away from a source of light is caused by a plant hormone called: