Maximum unguarded open walk / level change (per the answer key) before a **guard** is **required**: **760 mm**.
Choices
- (A) 760 mm
- (B) 1 050 mm
- (C) 915 mm
- (D) 550 mm
Correct answer: (A)
760 mm
Explanation
Key: 760 mm. Compare with *guard height* and *ramp* questions: different clauses.