This is the correct answer. It's sinosoidal and the frequency has to stay low enough that the time between peaks and troughs will necessitate that people continuously buy jeans and can't reuse the ones from the prior peak or trough.
This is the correct answer. It's sinosoidal and the frequency has to stay low enough that the time between peaks and troughs will necessitate that people continuously buy jeans and can't reuse the ones from the prior peak or trough.