Which one of the following may generally mean hardware ?

Word processor
Program
Operating system
Firmware

Firmware

The ability of a computer to handle more than one task at a go is called

multitasking.

Hardware typically refers to the physical components of a computer system. Among the options you provided, firmware is the one that generally refers to the software that is permanently programmed into the hardware of a device. Word processor, program, and operating system, on the other hand, are typically considered software components of a computer system.