Solution

The correct answer is option 3.

Key Points

Order of complexity. MIMD>SIMD>SISD

∴ Hence the correct answer is B, C, A.

Important Points 

Based on Flynn’s classification

MIMD (multiple instruction stream, multiple data stream):

This includes machines with multiple processing units that can apply multiple instructions to different data at the same time. The MIMD machines are the most complicated, but they also hold the most promise for increasing productivity by concurrent processing. Concurrency here means that not only are multiple processors running at the same time but also that multiple programs (processes) are running at the same time, concurrently.

SIMD (single instruction stream, multiple data stream):

This means that a single instruction is applied to several data sets at the same time. Many different processing units are activated by a single control unit in these machines.

SISD (single instruction stream, single data stream):

This is the von Neumann principle of serial computer architecture, which only executes one instruction at a time.