Answer:
==================================
Since all numbers are positive, their sum or product can be a positive number but never negative or zero.
- A) f + g = 2h, both sides are positive → true
- B) fh = 1, both sides are positive → true
- C) fgh = 0, at least one of the numbers should be zero → never true
- D) gh = 23, both sides are positive → true
