Which of the following describes the domain of f(x)=x−1+3−xf(x) = \sqrt{x-1} + \sqrt{3-x}f(x)=x−1+3−x?
x≥1x \ge 1x≥1
x≤3x \le 3x≤3
1≤x≤31 \le x \le 31≤x≤3
All real numbers