The part of machine level instruction that tells the central processor what to do is the:

The part of machine level instruction that tells the central processor what to do is the:

• Locator
• Source code
• Address
• Operation code 

EXPLANATION

The first element of a machine level instruction is almost always a fixed length collection of bits containing a code that identifies the specific operation to be performed 

 

While not all possible bit patterns that could appearin this operation code (or op code) field need necessarily be valid operation identifiers, the number of possible bit patterns provides an upper limit for the number of operations that the processor could support. For example, an 8-bit op code would limit a processor to a maximum of 256 different operations.