Pick out the wrong statement.

A. Longer tubes are less expensive per unit heat transfer area as compared to shorter tubes

B. A cost index is merely a number for a given year showing the cost at that time relative to a certain base year

C. Turnover ratio of a chemical plant is the ratio of gross annual sales to the fixed capital investment

D. Plates with butt welded joints are less expensive compared to lap welded joints, because squaring of plates is not necessary