A grading and utility project has uncertain quantities of rock excavation that cannot be measured accurately until digging begins. Which contract type is BEST suited?

Giải thích

Correct: a unit-price contract fits work with uncertain but measurable quantities; the owner pays the agreed rate for each unit actually installed or excavated. Lump-sum forces the contractor to guess the quantity and load the bid with risk. Open-ended cost-plus gives no cost control here. A fixed GMP without measuring the variable quantity does not match the uncertainty.