Which statement best distinguishes an agglutination reaction from a precipitation reaction?

Agglutination involves antigen–antibody interactions requiring complement to form visible aggregates on solid supports, whereas precipitation requires heat denaturation of antigens to allow lattice formation.

Agglutination occurs only in gels where antibodies and antigens diffuse toward each other to form a line of precipitate, whereas precipitation always occurs in liquid suspensions leading to visible cell clumping.

Agglutination detects only antibodies while precipitation detects only antigens; agglutination results are always reversible and precipitation results are always permanent.

Agglutination: antibodies cross-link antigens on large insoluble particles producing visible clumps; Precipitation: antibodies cross-link small soluble antigens into an insoluble lattice that precipitates out of solution.