SAT English Practice Question

The study of how the human brain remembers information, and the processes involved in the formation, storage, and retrieval of memories, is a complex and evolving field of research. Researchers have made significant progress in uncovering the mechanisms by which memories are encoded, consolidated, and recalled, but many mysteries remain. One particularly perplexing phenomenon is the so-called "tip-of-the-tongue" experience, in which individuals struggle to recall a specific word or piece of information, even though they are confident that they know it. While this experience is a common one, the exact neurological processes that underlie it are still not fully understood. What is the primary purpose of the passage?

1. A.describing the neurological processes underlying the "tip-of-the-tongue" experience.
2. B.explaining the methods used by researchers to study memory.
3. C.discussing the complexities of memory research and the limitations of current knowledge.
4. D.arguing that the "tip-of-the-tongue" experience is a common and universal one.