The correct option is C Five hundred and nine
Given, the farmer harvests 50 bags of corn cobs with each bag containing 10 corn cobs from his first field.
So, the number of corn cobs harvested from the first field = 50 times 10 = 50 tens = 5 hundreds = 500
Also, he harvests 9 corn cobs from the second field.
Total number of corn cobs harvested = 500 + 9
Thus, the total number of corn cobs harvested in words is five hundred and nine.