Final answer:
The most fitting topic for a middle adult client is financial planning, as it ensures preparedness for retirement, supports family needs, and contributes to societal roles during middle adulthood.
Step-by-step explanation:
The topic being taught to a middle adult client is likely to be financial planning. During middle adulthood, which spans from the 40s to mid-60s, individuals often focus on establishing stability for the future. Topics covered might include advanced directives, an essential part of end-of-life planning, and understanding one's finances as a component of financial literacy. Learning about financial planning helps ensure that middle adults are prepared for retirement, can support their families, and can contribute to society, aligning with the social task of generativity versus stagnation in middle adulthood.