The single accounting system is

A accounting system in which only one account is affected at a time
Initial stage of double entry
Special accounting system for small traders
An incomplete accounting system

The correct answer is: A. A accounting system in which only one account is affected at a time.

A single entry system is a type of accounting system in which only one account is affected at a time. This means that when a transaction occurs, only one account is debited and only one account is credited. This is in contrast to a double entry system, in which each transaction affects at least two accounts.

Single entry systems are often used by small businesses and individuals because they are simpler to understand and use than double entry systems. However, single entry systems are not as accurate as double entry systems, and they can be more difficult to track complex transactions.

Here is a brief explanation of each option:

  • Option B: Initial stage of double entry. This is incorrect because a single entry system is not the initial stage of double entry. Double entry systems have been around for centuries, while single entry systems are a relatively recent development.
  • Option C: Special accounting system for small traders. This is incorrect because single entry systems are not just for small traders. They can be used by businesses of all sizes, as well as individuals.
  • Option D: An incomplete accounting system. This is incorrect because single entry systems are not incomplete accounting systems. They are simply a different type of accounting system than double entry systems.