To solve this problem, we need to determine what the active form of Entamoeba histolytica feeds upon.$\newline$Entamoeba histolytica is a parasitic protozoan that causes amoebic dysentery in humans.$\newline$Let's analyze the feeding behavior of its active form, known as the trophozoite:$\newline \bullet$The trophozoite form of Entamoeba histolytica is known to invade the intestinal lining.$\newline \bullet$It feeds on erythrocytes (red blood cells), as well as the mucosa and submucosa layers of the colon.$\newline \bullet$This invasive behavior leads to the characteristic symptoms of amoebic dysentery, including bloody diarrhea.$\newline$Based on this information, the correct option is:$\newline$Option 1: Erythrocytes, mucosa and submucosa of colon.$\newline$Therefore, the correct answer is Option 1.