a plumbing system supplied by a 2 inch main contains 10 flush valves urinals, 20 tank water closets, 25 lavortories, and 3 drinking water fountains. the building owner wants an install additional 15 flush valves urnials to the system. what is the maximum number of urinals that can be added to sytem without modifying the main? A. 4 B.8 C.10 D. 14