Answer:
D. Chiasma
Explanation:
In Prophase I of Meiosis, a process called synapsis occurs. Synapsis is the process where homologous chromosomes pair up. Within this process, sister chromatids cross-over at certain points, and these points are called chiasmata. Chiasmata is just the plural of chiasma. In these points, the chromatids intertwine and exchange genetic material through a process called, cross-over.