The correct answer is A. Keypuncher.
A keypuncher is a person who operates a keypunch machine to convert data into punch cards. Punch cards were a primary medium for storing and inputting data into computers before the advent of magnetic tape and disk storage. As computers became more powerful and sophisticated, the need for keypunchers decreased. By the 1990s, keypunching was a largely obsolete occupation.
A data entry clerk is a person who enters data into a computer system. Data entry clerks typically use a keyboard to enter data into a spreadsheet, database, or other computer application. Data entry clerks may also be responsible for proofreading and correcting data entry errors.
A computer operator is a person who operates a computer system. Computer operators typically monitor the operation of a computer system and perform routine maintenance tasks. Computer operators may also be responsible for loading and unloading data and programs into a computer system.
A programmer is a person who writes computer programs. Programmers typically use a programming language to create instructions that a computer can understand and execute. Programmers may also be responsible for testing and debugging computer programs.
None of the above is not the correct answer because keypunchers were the data processing job expected to further decrease in the 1990s.