Final answer:
The correct answer is (b). An executive's different class from her parents is an example of intragenerational mobility, highlighting the social status change within a person's own lifespan.
Step-by-step explanation:
The question pertains to the concept of intragenerational mobility, which relates to the changes in social status that occur within an individual's lifetime. The correct answer to the question is:
(b) An executive belongs to a different class than her parents.
This option illustrates that an individual has experienced a change in social class that is different from the class of their parents within their own generation. In contrast, the other options do not signify a change in social status within the individual's lifetime, thereby not representing intragenerational mobility.