b. Find and interpret the standard deviation of the number of floors in this data set. Select the correct choice below and fill in the answer box within your choice. ​(Type an integer or decimal rounded to the nearest tenth as​ needed.) A. The standard deviation of the number of floors of the tallest buildings is nothing . B. The standard deviation of the number of floors per city is nothing . C. The standard deviation of the number of floors in each city is nothing . D. The standard deviation of the number of floors in each tallest building is nothing .