Alice, a project manager, has undertaken a project to build an irrigation canal. Based on the resources allocated to her, she makes an initial estimate that the time required to dig the canal would be 20 days. She also prepares an alternative estimate by adding an additional resource that will allow the project to be completed in 10 days. This alternative estimate that Alice prepares is referred to as the_________. 1. Crash duration. 2. Standard duration. 3. Slope duration. 4. Buffer duration. 5. Critical duration