Which passage from the article best supports the idea that setting a goal of getting 10,000 steps daily may not be ideal for everyone?

Back then, a Japanese company started selling a device called Manpo-kei, which translates as "10,000 steps meter."

The idea that people should aim for 10,000 steps daily for optimal health has been around for a while.
A study of teenagers showed that they enjoyed having a 10,000-step target but became discouraged when they were unable to reach it regularly.
Decades later, getting 10,000 steps in daily is ingrained in many people's minds as a key to better health.

A study of teenagers showed that they enjoyed having a 10,000-step target but became discouraged when they were unable to reach it regularly.