A contractor is excavating a trench that is 4.5 feet deep in soil that appears stable. A Competent Person has examined the ground and found no indication of potential cave-in. According to Cal/OSHA, is a protective system required?

• Yes, because all trenches deeper than 4 feet require protective systems
• No, because it meets the exception for trenches less than 5 feet deep examined by a Competent Person
• No, but only if a trench box is available on site
• Yes, because the trench is deeper than 4 feet