Final answer:
Dr. Blalock's actions in supporting Vivien Thomas can be seen as simultaneously contributing to racial advancement and existing within a context of systemic racism.
Step-by-step explanation:
Dr. Blalock's involvement in helping Vivien Thomas have a fulfilling career can be seen as a significant contribution to breaking down racial barriers in the medical field. Despite the prevailing racism and discrimination of the time, Black physicians faced tremendous challenges in receiving medical training and practicing medicine. However, it's important to note that Dr. Blalock's actions cannot be completely separated from the larger context of systemic racism and inequality that existed during that time.
While Dr. Blalock supported and mentored Vivien Thomas, it is also true that racism and discrimination persisted in medical institutions. Many Black doctors faced professional discrimination, limited opportunities, and inadequate access to resources and opportunities. Therefore, the answer to the question would be option 3) Both.