<s>[INST] context: The circumflex scapular aery, the dorsal scapular aery, and the suprascapular aery create aerial anastomoses around the scapula. This means that the scapula will be supplied with blood even if one of these aeries is ligated. Additionally, if the subclan or axillary aery needs to be ligated, blood can flow from the dorsal scapular aery and suprascapular aery to the circumflex scapular aery. This effectively shunts blood from the first pa of the subclan aery to the third pa of the axillary aery so that the upper limb will still receive blood. The connection between the suprascapular and circumflex scapular aeries is termed an open anastomosis because it is grossly visible, compared to the anastomosis with the dorsal scapular, which typically happens within small vessels. The anterior circumflex humeral aery supplies the deltoid muscle. It originates from the third pa of the axillary aery and anastomoses with the posterior circumflex humeral aery. The thoracodorsal aery is a branch of the subscapular aery that supplies latissimus dorsi. The transverse cervical aery is a branch of the thyrocervical trunk that occasionally gives rise to the dorsal scapular aery. None of these aeries contribute to the scapular anastomosis. [/INST] question: An open aerial anastomosis in the shoulder occurs between the suprascapular aery and which other aery? | options: A: Anterior circumflex humeral B: Circumflex scapular C: Dorsal scapular D: Thoracodorsal | answer: B </s>