What does the term "proficient" most closely mean?

The term "proficient" refers to having a high degree of competence or skill in a particular area or activity. When someone is described as proficient, it indicates they are above average in their ability, indicating a level of expertise in what they do. Therefore, "expert" aligns closely with this definition as it denotes someone who is highly knowledgeable and skilled in a specific field.

The other choices do not accurately capture the essence of being proficient. "Unskilled" suggests a lack of ability, "occasional" implies infrequency and does not relate to skill level, and "basic" indicates only a fundamental understanding rather than a high level of proficiency or expertise. Thus, expert is the term that most closely matches the meaning of proficient.