Final answer:
Symbolic Interactionist theories are most likely to be used in researching the development and maintenance of athletic identities due to their focus on micro-level interactions and meanings attributed to social roles and symbols.
Step-by-step explanation:
The theories most likely to be used in research on the process of developing and maintaining athletic identities are Symbolic Interactionist theories. These theories focus on the micro-level interactions between individuals, also considering the signs and symbols important in the communication of identity. Symbolic interactionism would analyze how athletes create and maintain their identities through daily interactions, the meaning they attribute to their roles, and how they interpret and give meaning to the social cues surrounding sports and athletics.
By contrast, Freudian theories focus on internal psychological processes and may be less relevant in a sociological study of athletic identities. Conflict theories highlight the role of power and inequality in shaping social identities, which could be relevant in discussing access to resources in sports or disparities within athletic institutions. However, it does not focus on day-to-day interactions as symbolic interactionism does. Opportunity theories could be relevant in discussing the chances and opportunities athletes have, but again, they do not specifically address the interpersonal dynamics of identity formation in the context of daily interactions.