A permanent memory, which has data and instruction to start up the computer and does not erase data after power off.

Computer memory is divided into types based on whether it keeps its contents when the power is switched off. Memory that loses its data when power is removed is called volatile; memory that keeps its data without power is non-volatile.

The description in the question, a permanent memory holding the instructions needed to start the computer and retaining that data even after power off, matches ROM (Read-Only Memory). ROM chips are pre-loaded with the startup instructions the computer needs the moment it is switched on, before an operating system has even loaded from disk.

RAM is the opposite: it is fast, temporary working memory that is erased every time the power goes off, so it cannot be the answer here. The CPU is the processor that executes instructions rather than a storage device, and a network interface card connects a computer to a network, so neither of these stores startup data.

A reliable way to separate ROM from RAM on any exam is to ask: does it survive a power cut? If yes, think ROM; if no, think RAM.