On what basis does separation occur in centrifugation?

Correct answer: By spinning force and density difference

The direct answer is A, separation by spinning force and density difference. Centrifugation is a physical separation method in which a sample is rotated rapidly. The rotation produces an outward effective force, and particles with different densities or sizes move and settle differently. Step by step: the sample is placed in a tube; the centrifuge spins it at high speed; denser or larger particles move toward the outer bottom region and form a pellet; lighter material remains above as liquid or supernatant. Thus cells, cell debris or other particles can be separated from a liquid. Option A is correct because spinning force and differences in density are the relevant basis. Option B, ‘song of color’, is meaningless and has no scientific role in centrifugation. Option C, smell of light, is not a physical property used for separation. Option D, sound of soil, is also unrelated. The exact movement can also depend on particle size, shape, medium viscosity and speed, but the school-level principle in this question is rotational force acting with density differences. Memory cue: centrifuge means ‘spin to separate’; heavier material generally moves outward and forms the pellet.