Final answer:
The question seems to be about anatomical structures visible in both right and left dorsal decubitus positions of the abdomen. The kidneys and associated large blood vessels like the aorta and inferior vena cava are typically visualized in these positions. However, without specific details, it's not possible to confirm which structures 1, 2, and 3 are, and thus the correct answer cannot be determined.
Step-by-step explanation:
The student's question pertains to structures that would be visualized in both right and left dorsal decubitus positions during imaging of the abdomen. In the dorsal decubitus position, one can visualize both the right and left anatomical structures that are symmetrical and not obscured by other tissues or organs. Given the information provided, it’s not fully clear what structures 1, 2, and 3 refer to as A, B, C, and D are the options presented. However, we can infer the structures typically visible in the dorsal decubitus positions may include the kidneys and associated large blood vessels such as the aorta and inferior vena cava, as mentioned in the provided Figure 19.3.2 which illustrates the abdominal cavity from the back of the body.
Using the additional information provided, the pleural cavity, as mentioned in review question 1, is part of the thoracic cavity, not the abdominal cavity. Therefore, it is not the subject of this question. Answer option 'D' which includes all components (1, 2, and 3) might suggest that both atria and ventricles or possibly another set of symmetrical organs are being referred to; however, without specific details, we cannot confirm the correct response to the student's original question.