How can we define addressability in the context of memory?

Addressability in the context of memory refers to the ability to uniquely identify each memory location within a system in order for the CPU or other hardware to access it. When we consider the options presented, the correct interpretation aligns with the concept that each memory location is assigned a distinct address, which is typically presented in hexadecimal format.

Hexadecimal addressing is common in computing because it provides a more compact representation of binary values, making it easier for programmers to work with memory addresses compared to decimal. Each address corresponds to a unique location in memory, which allows for efficient data retrieval and storage operations. This uniqueness is crucial for the operation of the computer system, as it ensures that when a specific address is referenced, the correct memory location is accessed.

In contrast, the other options portray different scenarios that do not accurately represent the general principles of memory addressability. For instance, unique decimal addresses are less commonly used in representation, certain memory locations being addressable does not reflect the nature of addressability itself, and shared addresses would lead to ambiguity and errors in accessing data. Hence, the concise and accurate understanding of addressability in memory is better represented by the unique hexadecimal addressing system employed in most computing architectures.