You Have Collected the Data for a Time-Cost CPM Scheduling

Multiple Choice

You have collected the data for a Time-Cost CPM Scheduling model analysis.The time is in days and the project "direct costs" are given below.
The indirect costs for the project are determined on a daily duration basis.If the project lasts 16 days the total indirect costs are $400,15 days they will be $250,14 days they will be $200,and 13 days they will be $100.At what day do we achieve the lowest total project cost (i.e. ,direct plus indirect costs) ?

A) 16 days
B) 15 days
C) 14 days
D) 13 days
E) 12 days