Answer:b)Humans can only learn a limited number of commands
Explanation: Programming problem are solved with various types of statement, commands, datatypes etc. In accordance with the human being , it is not easy for them to memorize complex and lengthy commands.
Due to numerous commands ,limited set of commands are used so that the user can be familiar with the command type and number of instruction .This will help them to learn the commands easily and find the solution for the programming problem.Thus, the correct option is option(b).