What does Vincent use to pass the genetic test at GATTACA?

Vincent uses a vial of Jerome's blood to pass the genetic test at GATTACA. Jerome, who is genetically engineered to be superior, provides Vincent with a means to bypass the strict genetic criteria implemented by the society in which they live. By using Jerome's blood, which belongs to a genetically elite individual, Vincent is able to successfully evade detection as a 'valid' human with lower genetic status. This act reflects the broader themes of the film, such as identity, genetic determinism, and the lengths to which individuals must go to pursue their dreams in a society that places heavy emphasis on genetic perfection. In the context of the other options, Vincent's own blood would have revealed his natural genetic flaws, his mother's DNA would not provide the necessary enhancements, and using his brother's blood would carry similar risks as his own. Hence, utilizing Jerome's blood is the pivotal action that enables Vincent to achieve his ambitions despite the oppressive genetic constraints of GATTACA.