Final answer:
The correct answer is fad.
Step-by-step explanation:
The correct answer is fad.
A fad refers to a temporary and highly popular trend or fashion that gains rapid popularity but eventually fades away. Bell-bottoms were widely fashionable in the past but are no longer considered stylish in the present.
Other options given in the question, such as extended fad, recursive cycle, classics, and normal cycle, do not accurately describe the nature of bell-bottoms in relation to fashion trends.
Learn more about the nature of fashion trends