Explanation:

diplotene

Chiasmata is the point of contact between two non-sister chromatids belonging to homologous chromosomes. Chiasmata are visible only in the diplotene stage of prophase I of meiosis. In pachytene stage actual crossover of genetic material happens. Leptotene is the first stage of meiosis where chromosomes are seen as threads while Zygotene is the second stage of meiosis where homologous chromosomes start pairing.