Final answer:
Option D, which refers to the hiring of additional retail staff during the fall and winter seasons due to increased consumer demand, best describes an example of seasonal unemployment. This type of unemployment is due to the fluctuations in employment based on seasonal factors.
Step-by-step explanation:
The best description of an example of seasonal unemployment is option D: Retail stores often expand their workforce during fall and winter due to increased consumer demand. Seasonal unemployment refers to a situation where workers find employment only during certain seasons or periods of the year, due to the nature of their jobs being related to specific seasons.
For instance, retail stores typically hire additional staff during the holiday season to handle the increased shopping traffic. After the season ends, there's a reduction in demand which results in these additional employees being laid off.