Low-level coding means that...
a.) a component item is coded at the lowest level at which it appears in the BOM structure
b.) a final item has only a few levels in the BOM structure
c.) the lowest-paid staff member in the production department performs the coding
d.) the code being used is the code for the lowest level in the BOM structure

a.) a component item is coded at the lowest level at which it appears in the BOM structure is the correct answer.

Explanation:

Low-level coding is a kind of programming language used in BOM structures and it carries basic commands that are identified by a computer.The two types of low-level coding areAssembly language.machine language.The advantages of using low-level coding are programs develop by using low-level code are very memory effective and quick and there no need to use interpreters for the conversion of the source to machine code.