A is the addition of all the entries, B is the number of entries that said snakes, C and D are about how many out of the total can give you the corresponding animal, chances are always part/total so for C it's 9/31 and D is 2/31. E is 0 or unknown because there is no "Frog" entries as favorite pet so it must be either 0 or unknown because you don't get the information