Clay particles are able to attract charged or polar organic molecules. researchers have demonstrated that the concentration of organic molecules by the process of can facilitate their assembly into macro molecules.
a. evaporation
b. adhesion
c. dehydration synthesis

Answer is Option C.

The concentration of organic molecules by the process of dehydration synthesis can facilitate their assembly into macro molecules.

Explanation:

Macromolecules are large molecules formed by covalent bonds between monomers. They are a growing chain of monomers assemble through a process called dehydration synthesis in which one monomer forms a covalent bond with another monomer by releasing a water molecule. This is a process that requires energy. For example, two glucose molecules (monomers) combine to form a single maltose molecule. As a new covalent bond forms between the two glucose molecules, a water molecule is released.

Evaporation is a process in which water vapor is formed from water. The tendency of dissimilar particles to stick together is known as adhesion.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.