Explanation:

Understanding, knowledge, and reasoning power:
Understanding, knowledge, and reasoning power are qualities that are associated with intellectual individuals. Intellectuals are known for their ability to comprehend complex ideas, acquire knowledge in various fields, and apply critical thinking and reasoning skills to solve problems. These individuals have a deep curiosity and desire to learn and understand the world around them.

Expert:
While an expert is someone who has mastered a specific field or topic, being an expert does not necessarily imply having good understanding, knowledge, and reasoning power in general. An expert may have a deep understanding and knowledge in their specialized area, but their expertise may not extend to other domains. Therefore, being an expert does not necessarily encompass the broad range of qualities mentioned in the question.

Literate:
Literate individuals are those who possess the ability to read and write. While literacy is an important skill, it does not directly imply good understanding, knowledge, and reasoning power. Literacy is a foundational skill that enables individuals to access and comprehend information, but it does not necessarily guarantee a high level of intellectual ability.

Snob:
A snob is someone who believes they are superior to others based on their social status, wealth, or perceived superiority in taste or knowledge. While a snob may consider themselves to be knowledgeable or have a good understanding, their attitude of superiority often stems from arrogance rather than genuine intellectual capacity. Snobbery is not synonymous with possessing good understanding, knowledge, and reasoning power.

Intellectual:
The correct answer is 'Intellectual' because it encompasses the qualities mentioned in the question. An intellectual person is someone who has good understanding, knowledge, and reasoning power. They possess a broad range of knowledge and have the ability to think critically and analyze complex ideas. Intellectuals are known for their curiosity, open-mindedness, and capacity for lifelong learning. They seek to deepen their understanding and engage in intellectual pursuits.