Given the following information: Back-to-back water closets Roughed-in dimensions: 254 mm (10 in.) from finished walls Hollow tile partition: 125 mm (5 in.) Plaster wall finish: 19 mm (3/4 in.) What is the centre-to-centre distance of the water closet flanges? A. Metric 335 mm; Imperial 13 1/4 in. B. Metric 633 mm; Imperial 25 in. C. Metric 671 mm; Imperial 26 1/2 in. D. Metric 796 mm; Imperial 31 1/2 in