Correct Answer: Extrinsic

Solution : The correct solution is the third option.

Explanation: Intrinsic motivation refers to motivation that comes from within, driven by personal interest, enjoyment, or the inherent satisfaction of the task itself. The antonym of intrinsic, in the context of motivation, is extrinsic which involves external factors such as rewards, punishments, or recognition influencing behaviour.

So, the correct sentence would be: One must aim to develop extrinsic motivation within learners for better retention of knowledge.

The meanings of the other options are as follows:

• Elemental: It refers to basic or essential elements.

• Introjected: It refers to internalising external values or beliefs.

• Inherent: It refers to the idea of something being essential or inherent to a person or thing.