The correct answer is C. Open Source Software.
Open source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open source software is often developed in a public, collaborative manner.
A. Open System Software is not a correct answer. Open system software is a type of software that is designed to be compatible with a variety of hardware and software platforms.
B. Original Source Software is not a correct answer. Original source software is the source code of a computer program that is written by the original author of the program.
D. Original System Server is not a correct answer. An original system server is a computer that is used to host the operating system and other software for a computer network.
E. None of the above is not a correct answer.