While completing a project a project manager realizes be needs to decrease project costs. After researching his options, he comes up with the following choices. Which choice would DECREASE project costs ？（）
A．Change to component A from component B. Component A costs more to purchase but has a lower life cycle cost than B
B．Change task A to be completed by resource B instead of Resource C, Resource B is a more experienced worker
C．Move tasks B and H to occur concurrently, and take the risk of a 30% increase in the need for five more resources later
D．Remove a test from the project plan