Practice question

Go with B — 150,000–400,000. Within Blood and their Component, that statement lines up with the standard definition and the usual exam wording you’ll see. In plain terms, 150,000–400,000 is the option that correctly names the structure, process, or principle asked for in Blood and their Component. Holding that picture in mind makes 150,000–400,000 feel natural rather than something you only memorise. Link the term to a real body example (organ, tissue, or ion flow) so the idea stays concrete under exam pressure. A short mental diagram helps — start from stimulus or structure, follow the pathway, and stop at the functional result described by 150,000–400,000.