Answer : Option A
Explanation :
Before IBM created its personal computer, two types of computer systems, Apple II and CP-M, dominated the microcomputer world. Neither of these systems were PC compatible, or Mac-compatible (the two primary standards in place today). The original IBM PC became a new standard in the microcomputer industry. Since then, hundreds of millions of PC-compatible systems have been sold, as the original PC grew into a large family of computers and peripherals. More software has been written for this computer family than for any other system on the market.