The correct answer is: A. keypunch machine, sorter, and posting machine.
A punched card system is a data processing system that uses punched cards to store and process data. The data is entered into the system by a keypunch machine, which punches holes in the cards according to the data that is entered. The cards are then sorted by a sorter, which arranges them in a specific order. The cards are then posted to a ledger, which is a book that contains the data that is being processed.
The other options are incorrect because they do not include a keypunch machine. A keypunch machine is necessary to enter the data into the system. The other machines are used to sort and post the data, but they cannot enter the data into the system.
Here is a brief description of each option:
- A keypunch machine is a machine that punches holes in cards according to the data that is entered.
- A sorter is a machine that arranges cards in a specific order.
- A posting machine is a machine that posts data to a ledger.
- An accounting machine is a machine that performs accounting tasks, such as adding, subtracting, and multiplying.
- A billing machine is a machine that prints bills.