You are the project manager for the construction of a new thin-crust pizza vending machine,You take all the information gathered in the project management plan to date and begin to develop a project schedule, When you reach the activity labeled as 6.5.3, you are unsure if a refrigeration specialist is needed for the installation of the cooling mechanism for the pizza dough. What project document would you reference in order to get information on the resources required for installing the cooling mechanism? a. Resource calendar b. Activity attributes c. Procurement management plan d. Resource management plan