To solve this problem, we need to identify the correct sequence of organs in the alimentary canal of a cockroach, starting from the mouth. Let's analyze the options and understand the sequence:$\newline \bullet\$The alimentary canal of a cockroach is divided into three main regions: foregut, midgut, and hindgut.$\newline \bullet\$The sequence of organs in the alimentary canal is as follows:$\newline$Mouth: The starting point of the alimentary canal.$\newline$Pharynx: A short tube that connects the mouth to the oesophagus.$\newline$Oesophagus: A narrow tube that carries food from the pharynx to the crop.$\newline$Crop: A storage organ where food is temporarily stored.$\newline$Gizzard: A muscular organ that grinds the food.$\newline$Midgut (Ileum): The region where digestion and absorption occur.$\newline$Hindgut (Colon and Rectum): The region where water absorption occurs and feces are formed.$\newline\newline$Now, let's match this sequence with the options provided:$\newline \textbf{Option 1:} Pharynx \rightarrow Oesophagus \rightarrow Crop \rightarrow Gizzard \rightarrow Ileum \rightarrow Colon \rightarrow Rectum \newline$This sequence correctly follows the anatomical structure of the cockroach's alimentary canal.$\newline \textbf{Option 2:} Pharynx \rightarrow Oesophagus \rightarrow Gizzard \rightarrow Crop \rightarrow Ileum \rightarrow Colon \rightarrow Rectum \newline$This sequence incorrectly places the gizzard before the crop.$\newline \textbf{Option 3:} Pharynx \rightarrow Oesophagus \rightarrow Gizzard \rightarrow Ileum \rightarrow Crop \rightarrow Colon \rightarrow Rectum \newline$This sequence incorrectly places the gizzard before the ileum and the crop after the ileum.$\newline \textbf{Option 4:} Pharynx \rightarrow Oesophagus \rightarrow Ileum \rightarrow Crop \rightarrow Gizzard \rightarrow Colon \rightarrow Rectum \newline$This sequence incorrectly places the ileum before the crop and gizzard.$\newline\newline \textbf{Therefore, the correct sequence is given in Option 1:} Pharynx \rightarrow Oesophagus \rightarrow Crop \rightarrow Gizzard \rightarrow Ileum \rightarrow Colon \rightarrow Rectum.$