The correct answer is C. Intel Pentium.

The MMX instruction set is an extension to the x86 instruction set architecture designed by Intel for multimedia processing. It was first implemented in the Intel Pentium MMX processor in 1997. MMX instructions allow the processor to perform arithmetic and logical operations on packed data, such as 4-byte integers or 2-byte floating-point numbers. This can significantly improve the performance of multimedia applications, such as video encoding and decoding, audio processing, and image processing.

The 8080 is a 16-bit microprocessor that was introduced in 1974. It does not support MMX instructions.

The 80486 is a 32-bit microprocessor that was introduced in 1989. It does not support MMX instructions.

The 80386 is a 32-bit microprocessor that was introduced in 1985. It does not support MMX instructions.

The Pentium is a series of microprocessors that was introduced by Intel in 1993. The first Pentium processor did not support MMX instructions, but MMX support was added in the Pentium MMX processor, which was introduced in 1997.