20. The zookeeper divides a pile of peaches among several monkeys. If each monkey gets 6 peaches, there are 57 peaches left. If each monkey gets 9 peaches, 5 monkeys get none, and one monkey gets only 3. Therefore, there are ( ) peaches.
A. 216
B. 324
C. 273
D. 301
【Answer】Solution: According to the problem, we know:
If each monkey gets 6 peaches, there will be 57 peaches left. If each monkey gets 9 peaches, 5 monkeys will get none, and one monkey will only get 3, proving a shortage of $5 \times 9+6=51$;

The total number of peaches is $36 \times 6+57=273$.
Therefore, the answer is: $C$.