Final answer:
The best detail supporting the use of molecular scissors in fixing human embryos is the explanation of how the process works, directly relating to gene editing technologies used for treating genetic diseases. Ethical, social or medical considerations also play a substantial role.
Step-by-step explanation:
The detail from the text that best supports the answer to the question 'Molecular scissors fix disease-causing flaw in human embryos' is that the text explains the process of using molecular scissors to fix disease-causing flaws in human embryos. This indicates concrete information about how the molecular scissors function, making it the most relevant detail among the options provided. Gene editing technologies like CRISPR can specifically target and correct genetic defects, which is an important aspect of modern biotechnology and can lead to treatments for diseases with genetic causes such as cystic fibrosis, hemophilia, muscular dystrophy, and sickle cell anemia.
Furthermore, in the context of gene editing, it's crucial to consider ethical, social or medical issues associated with such powerful technology. Weighing the benefits of potentially eliminating genetic diseases against ethical concerns about manipulating human genomes is a critical part of ongoing discussions in the scientific community.