The transition from acute to adaptive phase is which of the following?

• A. Abrupt
• B. Immediate
• C. After several weeks
• D. Gradual

Answer: (D)

The transition from acute to adaptive phase happens gradually. Immediately after injury or infection, innate defenses act quickly to contain damage and recruit immune cells. The adaptive response—antigen-specific T and B cell activation, clonal expansion, and antibody production—unfolds over several days to weeks as these cells are activated, proliferate, and differentiate. Because this shift depends on antigen presentation and lymphocyte proliferation, it cannot be immediate or abrupt, and it typically isn’t delayed for weeks beyond the normal course. So the best description is that the transition is gradual.