Buddhism spread to Tibet

Choose one of the following topics:
1. Discuss the historical conditions and context under which Buddhism spread to Tibet and why the Tibetans adopted Buddhism as their national religion.
2. Describe and discuss (or compare) characteristics of the specific Tibetan Buddhist path (view, meditation, and conduct) of one (or more) of the four Tibetan Buddhist schools (Nyingma, Kagyii, Gelug and Sakya).
3. Describe and explain how the Tibetans adopted and indigenized Indian Buddhism (Mahayana and Vajrayana).