The leader nodded his approbation.

understanding
approval
admiration
appreciation

The correct answer is: B. approval.

Approbation is a feeling of favorable judgment or approval. It is often expressed through words or actions, such as nodding one’s head.

Understanding is the ability to comprehend something. It can be expressed through words, actions, or even just a look.

Admiration is a feeling of respect or high regard for someone or

something. It is often expressed through words, actions, or even just a smile.

Appreciation is a feeling of gratitude or thankfulness. It is often expressed through words, actions, or even just a hug.

In the context of the question, the leader is nodding his head in approval. This means that he is favorably judging or approving of something.