What is the main difference between primary memory and secondary storage?

Correct answer: Primary memory directly supports processing while secondary storage keeps long-term data

The governing concept is the different role and access pattern of memory types. Primary memory, such as RAM and cache, provides the CPU with relatively fast access to instructions and data currently needed for processing. Secondary storage, such as an SSD, hard drive, or memory card, keeps files and programs for long-term use and normally retains them without power. Therefore, option D is correct; the other choices confuse storage with printing, networking, or computation.