Final answer:
The term describing DNA segments exchanged between non-sister chromatids of homologous chromosomes during prophase I of meiosis is 'crossing over', which leads to genetic recombination. The correct option is b.
Step-by-step explanation:
The term used to describe the event when segments of DNA are exchanged between non-sister chromatids of homologous chromosomes is known as crossing over. This process occurs during prophase I of meiosis, where homologous chromosomes line up in pairs and form tetrads.
Crossing over leads to the exchange of genetic material between non-sister chromatids, after which material breaks off from one chromatid and reattaches to the same position on the homologous chromosome, resulting in genetic recombination.
This genetic recombination contributes to the genetic diversity seen in sexually reproducing organisms. Option b. is the correct one.