Logs Are Stacked So That There Are 21 Logs in the Bottom

Multiple Choice

Logs are stacked so that there are 21 logs in the bottom row, 20 logs in the second row from the bottom, and so on, decreasing by 1 log each row.How many logs are there in the first four rows from the bottom?

A) 140 logs
B) 60 logs
C) 78 logs
D) 153 logs
E) 165 logs