Final answer:
The uppermost border of the manubrium is called the jugular notch and it corresponds to the level of T2-T3 vertebrae, making the correct answer a) Sternal angle, jugular notch, T2-T3 vertebrae.
Step-by-step explanation:
The uppermost border of the manubrium is called the jugular notch, also referred to as the suprasternal notch or manubrium notch, and it corresponds to the level of the T2-T3 vertebrae. Options a), b), c), and d) presented in the question are varying combinations of terms and spinal levels. Considering anatomical structures and alignment, the correct answer is a) Sternal angle, jugular notch, T2-T3 vertebrae.
The sternum is an elongated bony structure in the anterior thoracic cage, comprised of three parts: the manubrium, body, and xiphoid process. The manubrium, being the upper part, joins with the body of the sternum at the sternal angle, and the jugular notch is situated at the top of the manubrium. The sternal angle is also a significant anatomical landmark because it is the junction between the manubrium and the body of the sternum and at the level where the second rib is attached to the sternum.