Convert the Store and Regional Sales database to an Excel table. For the Store and Regional Sales database, apply a four traffic light icon set to visualize the distribution of the number of units sold for each store, where green corresponds to at least 30 units sold, yellow to at least 20 but less than 30, red to at least 10 but less than 20, and black to below 10 to find:

a. The total number of units sold

b. The total number of units sold in the South region

c. The total number of units sold in December.