Among the following. the example of a conditioned reflex is :

The correct option is D

Picking up of a stone scares away a dog

The correct option is D:

Explanation of the correct option:

1. The acquired reflexes that are controlled by a stimulus are called the conditioned stimulus
2. Salivation is a hungry dog in response to ringing a bell or Picking up a stone scares away a dog is an example of the conditioned reflex.

Explanation of the incorrect option:

Option A:

1. The response obtained on a given stimulus is called unconditioned reflex.
2. Pulling of the hand when pricked with a needle is an example of an unconditioned reflex.

Option B:

Closing of eyes when some object falls into any one of them is an example of an unconditioned reflex.

Option C:

The movement of food in the alimentary canal is an example of an unconditioned reflex.

Final answer: Picking up a stone that scares away a dog is an example of the conditioned reflex.