Schistocytes are defined as fragmented red blood cells and can be present in different shapes. With this information, we can proceed to analyze the available options.
-Decreased red cell proliferation: This cannot be because there is no fragmentation.
-Increased iron mobilization: This cannot be because there is no mention of the red cell state
-Decreased erythropoietin activity: This cannot be because is a glycoprotein that stimulates the formation of erythrocytes.
-Increased red cell destruction​: This is the correct option as schistocytes are fragmented red blood cells. The causes can be varied such as damaged endothelium.