Which of the following statements about f(x) = sin(π/4 x) is true?

- The graph of f is increasing on 0 ≤ x ≤ 4 and also on 16 ≤ x ≤ 20 because these intervals are separated by a length of exactly one period.
- The graph of f is increasing on 0 ≤ x ≤ 4 and also on 16 ≤ x ≤ 20 because these intervals are separated by a length of exactly 2π units.
- The graph of f is increasing on -2 ≤ x ≤ 2 and also on 6 ≤ x ≤ 10 because these intervals are separated by a length of exactly one period.
- The graph of f is increasing on -2 ≤ x ≤ 2 and also on 6 ≤ x ≤ 10 because these intervals are separated by a length of exactly 2π units.