Which process breaks down complex substances into simpler components?

The process that effectively breaks down complex substances into simpler components is known as dissolution. During dissolution, a solute (which can be a complex substance) interacts with a solvent, leading to the separation of the solute's molecules and forming a homogeneous mixture. This is particularly important in biological systems where complex molecules like proteins or carbohydrates need to be broken down into simpler forms such as amino acids or sugars to be utilized by the body.

Absorption refers to the process through which substances are taken up by cells or tissues, typically after they have been dissolved in bodily fluids. Thus, it does not directly involve the breakdown of substances into simpler forms.

Diffusion is the process by which molecules spread from an area of high concentration to an area of low concentration. While it is essential for the movement of substances within biological systems, it does not specifically concern the breakdown of complex substances.

Filtration is a method used to separate particles from a fluid by passing the fluid through a medium that retains the particles. It is more about the physical separation of substances rather than a chemical breakdown into simpler components.

In summary, dissolution is the process that correctly describes the breakdown of complex substances into simpler components, making it distinct from the other listed processes.