Alice is having difficulty selling herself to employers. Her counselor concludes that her reticent nature reflects her Realistic rather than Enterprising personality. Her counselor is using

Holland's theory.

Explanation:

Holland's theory is explained to be a vocational theory in development of a persons career. It explains how a persons behavioural attitude and working ethics should emerge to make the said person a better expert in his/her field of expertise. This theory was been formulated on fundamentals that humans possess certain behaviours, interests, traits, and other attributes that can be arranged in different groupings which are termed to be Realistic, Investigative, Artistic, Social, Enterprising, and Conventional which has the acronym RIASEC. They tend to analyze and classify a person better.