Question

in the absence of other information, all soils in an excavation should be treated as if they were _____.
○ type a
○ type c
○ solid rock
○ type b

Explanation:

In excavation safety standards, when there's no other information about soil type, the default assumption for soils is type C (which is the least stable and most hazardous in terms of potential for collapse, so it's the conservative default to ensure safety). Type A is more stable, type B is intermediate, and solid rock isn't the default for general soil excavation without info.

Answer:

B. type C