After the embryos are screened by Marie, how many healthy ones remain?

In the context of the narrative in "GATTACA," after the embryos are screened by the geneticist Marie, the number of healthy embryos that remain is a crucial aspect of the storyline. The screening process is designed to identify embryos that are free from genetic disorders, and only those that meet the health criteria will be selected for implantation.

The answer of four healthy embryos reflects the film's emphasis on the genetic engineering aspect of human reproduction, showcasing the possibility of selecting against various genetic disorders. This selection process is fundamental to the society depicted in "GATTACA," where genetic perfection is highly valued. Thus, having four healthy embryos emphasizes the success rate of the screening process and highlights the ethical and societal implications of genetic selection.

In the broader context of the film, this also serves to illustrate the philosophical and ethical debates surrounding genetic manipulation and the implications of choice in human reproduction. The concept of how many embryos remain healthy ties directly into the central themes of identity and the predetermined nature of individuals based on their genetic makeup.