Solution:
It is done by Operating system.
An Operating system is system software that manages computer hardware and software resources and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.
For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers.
Answer:
Option 4 is correct ,=(B2+C9)
Explanation:
In excel a formula starts with an equal sign followed by the expression.
In first option the formula is incorrect inside the brackets. where 4 is equating to bracket. In 2nd option opening and closing brackets are not same. First closing bracket is missing an opening bracket. In third option all the formula is correct except the part where # is used in formula. Hash tags cannot be used in formula as a value. Here in option D B2 and C9 are cell in excel, whereas parentheses are only used for better readability.