What is a 32-bit operating system capable of addressing?

A 32-bit operating system is capable of addressing up to 4 GB of address space due to the way memory addressing works. In a 32-bit system, addresses are represented using 32 bits, which allows for (2^{32}) different addressable locations. This calculation results in a total of 4,294,967,296 possible addresses, which is equivalent to 4 GB of addressable memory space.

The reason this limit is significant is that it defines how much memory the operating system can use at any given time. With only 32 bits available for addressing, systems cannot go beyond this limitation, meaning that even if more physical memory is installed, the operating system will not be able to utilize it fully.

In contrast, options suggesting lower capacities pertain to memory limitations imposed by specific operating systems or hardware configurations, but they do not reflect the theoretical maximum a 32-bit system can address. The option indicating unlimited address space is also incorrect, as it contradicts the very limitation inherent in a 32-bit architecture. Thus, the correct understanding of a 32-bit operating system leads to the conclusion that it can indeed address up to 4 GB of address space.