Step 1: Understanding the characteristics.
The question describes a person who possesses good understanding, knowledge, and reasoning power. This refers to someone who is capable of thinking critically and has deep intellectual abilities.
Step 2: Analyzing the options.
(A) Expert: An expert is someone who has specialized knowledge in a particular area but doesn't necessarily imply general understanding or reasoning power.
(B) Intellectual: Correct — An intellectual is someone who engages in critical thinking and has a high capacity for reasoning, knowledge, and understanding.
(C) Snob: A snob is someone who looks down on others based on their perceived social status or education, but it doesn't relate to good reasoning or intellectual abilities.
(D) Literate: Being literate means being able to read and write, but it doesn't necessarily imply the ability to reason or have deep knowledge.
Step 3: Conclusion.
The correct answer is (B) Intellectual, as it best describes a person with good understanding, knowledge, and reasoning power.