Welcome to Westonci.ca, the ultimate question and answer platform. Get expert answers to your questions quickly and accurately. Discover in-depth answers to your questions from a wide network of professionals on our user-friendly Q&A platform. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

20. Reduction of one's ability to exercise or perform work begins at the high altitude of
a. 3, 0 feet above sea level.
b. 3,500 feet above sea level.
C. 4,000 feet above sea level.
d. 5,000 feet above sea level.