Final answer:
The characteristics of ROM are that it is nonvolatile, meaning data is retained without power, and it typically houses the BIOS and system clock settings.
Step-by-step explanation:
The question relates to the characteristics of Read-only memory (ROM). The correct characteristics are that ROM is nonvolatile and it often contains the Basic Input/Output System (BIOS) and settings for the system clock. Nonvolatile means that ROM retains its data even when the power is turned off, and the BIOS is a critical piece of software that interfaces between the computer's firmware and its operating system. Therefore, the correct answer to the characteristics of ROM are (A) nonvolatile and has BIOS and system clock on it.