Consider what the text says. It is dangerous to presume upon opportunities of the future. Today's young athletes too often bail out of college for mega-bucks and forsake their education. It is right to plan, but wrong to presume. B. Dangerous to presume upon the place.
Shopping malls go out of business.
C. Dangerous to presume upon time. Only God knows whether we have another year to live or whether our workload will be reduced to provide more leisure time. It still is true that time is the stuff life is made of. Yesterday is a canceled check. Tomorrow is a promissory note.