Final answer:
The concept of adjusting approach according to the client's health literacy (OACA) applies to the field of Public Health.
Step-by-step explanation:
The concept of adjusting approach according to the client's health literacy (OACA) applies to the field of Public Health. Health literacy refers to an individual's ability to understand and use health information to make informed decisions about their health. In the field of public health, it is crucial to consider the health literacy levels of the population you are working with in order to effectively communicate health information and promote healthy behaviors.