Which of the following x-ray examinations would give the patient the highest bone marrow dose?

Choosing the abdomen as the examination that would give the patient the highest bone marrow dose is grounded in the understanding of radiation exposure based on body regions and the sensitivity of tissues. The abdomen houses several critical structures, including the spine, pelvis, and major organs, which are close to the bone marrow areas, particularly in the hips and lower spine where hematopoietic tissue is abundant.

X-ray examinations of the abdomen not only involve the exposure of more substantial soft tissue but also can lead to a higher radiation scatter effect that impacts the bone marrow compared to the other listed examinations. In contrast, x-rays of the chest, head, and extremities typically involve less surrounding soft tissue and bone marrow proximity, resulting in lower doses to the bone marrow.

The highest bone marrow doses are thus attributed to examinations that cover larger body areas with denser bone marrow presence, making the abdomen the examination that yields the highest exposure in this regard.