20. The process in which antibodies attach to antigens, causing the formation of masses of linked cells is called __ 1. sensitization 2 coagulation 3. agglutination 4. hemolysis

## Step 1<br />The problem is asking for the term that describes the process where antibodies attach to antigens, leading to the formation of masses of linked cells. This process is known as agglutination.<br /><br />## Step 2<br />Let's go through the other options as well:<br />1. Sensitization refers to the process where the immune system becomes more responsive to a specific antigen. This is not the process described in the problem.<br />2. Coagulation is the process where blood changes from a liquid to a gel, forming a clot. This is not the process described in the problem.<br />4. Hemolysis is the rupture or destruction of red blood cells. This is not the process described in the problem.