Command, operation, procedure, process - part 1

Type the correct number which matches the phrase to complete the following sentences:

A) A command is ____, for example, PRINT. A -- 1. a series of changes which produce a result at the end
B) An operation is _____, for example, addition. B -- 2. a mathematical change
C) A procedure is ____, for example, logging in. C -- 3. an instruction for a computer
D) A process is ____, for example, printing a document. D -- 4. a correct way to do something