Alejandro reached the platform just as the train's doors closed. He would have made it in time had it not been for his crutches. Had it not been for his stupid injury, he would have been on that train. Instead he was stuck on the platform, waiting all by himself. Since the injury, not a day had passed that he hadn't been reminded of his poor luck. He was a perfectly healthy 22 year old, supposedly in the prime of his life. And yet, while playing soccer with his friends, he'd fallen and torn his ACL, a ligament in his knee. As a result, he'd been sentenced to three months of physical therapy and a long, slow recovery. Alejandro felt as if his body had betrayed him. Injuries like this were supposed to happen to old out-of-shape guys—but not to him. And the physical therapy was a nightmare. His therapist, Dr. Mike, expected him to do a full hour of stretches every day. A full hour! Alejandro barely had the patience for 15 minutes of stretching. "You're not used to being injured, are you?" Dr. Mike had asked him during their first meeting. "Of course not," Alejandro had responded. "I'm in great shape." "Even world-class athletes get injured," Dr. Mike said. "The first step on the road to recovery is to the take the time to recover. We can't push our bodies too far. From there, we should learn acceptance. Our bodies don't last forever. The sooner you accept this fact, the sooner you will heal. Plus, you'll be better equipped to deal with injuries in the future." Now, as Alejandro waited for the next train, he had time to contemplate Dr. Mike's advice. People had always told Alejandro to appreciate his youth while he had it. But Dr. Mike was saying something else. He was telling Alejandro to prepare for a day when his body would fail. Dr. Mike was telling Alejandro to accept his body's shortcomings, even though he was still young. As these thoughts occurred to Alejandro, an old man appeared on the train platform. He made his way slowly toward Alejandro, using a cane to support his weight. His body was hunched, and a hump was visible in his back. And though his cautious, deliberate progress across the platform was painful to watch, Alejandro noticed that the old man was smiling. The old man reached Alejandro just as the next train arrived. Alejandro nodded at him respectfully. Then the two of them boarded the same car: Alejandro with his crutches, and the old man with his cane.

A theme of this selection is
A. patience is the best medicine.
B. good opportunities are rare.
C. life is mysterious and strange.
D. a healthy body lasts forever.