Final answer:
Research identifies gaps in the applicability of existing models and methods of social work practice, as it involves systematic data gathering and analysis to improve social work interventions. The correct option is B.
Step-by-step explanation:
The answer to the question, which is about identifying gaps in the applicability of existing models and methods of social work practice, is Research (Option B).
Research plays a crucial role in social work as it seeks to understand various aspects of social issues and the effectiveness of social work interventions.
It involves systematically gathering and analyzing data to generate evidence that can be used to improve practices, policies, and client outcomes.
Case studies, while valuable for in-depth analysis, do not inherently identify gaps in applicability but rather provide rich, contextual insights into particular instances or phenomena.
Evaluation, while important for assessing the impact of existing interventions, initiatives, or programs, is not the primary means of identifying gaps in models or methods themselves. Instead, it serves to measure how effective these interventions are. The correct option is B.