Final answer:
Juanita's higher pay is most likely explained by compensation differentials and efficiency wages (A) or compensation differentials and natural ability (D), suggesting that either her skills are particularly valued or she exhibits high productivity that her employer is willing to compensate more generously for.
Step-by-step explanation:
To determine which concepts can explain Juanita's higher pay compared to her colleagues, we need to consider the relevant economic theories and labor market practices. Concept A involves compensation differentials and efficiency wages, suggesting Juanita may be paid more because her skills are in higher demand or her employer is paying above market rate for increased productivity or loyalty. Concept D involves compensation differentials and natural ability, which implies that Juanita's unique talents or higher productivity levels could explain her higher wages.
Concepts involving discrimination (B and C) suggest that unfair treatment based on gender, race, or effort could result in different pay rates, but these concepts are not supported by the information provided which highlights comparable levels of education, experience, and expertise for those employed. Moreover, the evidence suggests that discrimination in pay would typically result in lower rather than higher wages for those discriminated against.
Therefore, given the context provided that does not indicate discrimination, the concepts explaining Juanita's higher pay are more likely associated with either her possessing in-demand skills or abilities that result in compensation differentials (A or D) or her being rewarded for efficiency that benefits her employer (A).