If you've decided you want to improve your fitness, walking is a good choice. It's free, simple, and adaptable to your schedule. If you've been relatively sedentary, you might find that you can't walk very far at first without getting sore or out-of-breath. You just have to keep at it! If you try to walk a little further every day, you'll find that your walking stamina gradually improves. If you don't have the patience for that, there are a few other tricks you can try to help you reach your goals faster.

According to the passage, what might the “tricks” mentioned in the last sentence refer to?

A) methods to improve your stamina quickly.

B) suggestions on how to keep fit.

C) benefits of different styles of walking.

D) different ways to build up your stamina over a long period.