According to the plan, 1000 hours of the work should be done with the fee of US$50 per hour by now. The project manager calculated the actual cost and realized that the team has completed the work of 1200 hours with US$40,000 according to the fee of US$50 per hour .What is the cost performance index of the project ?
	A、1.5
	B、1.2
	C、0.833
	D、0.667