I believe that it is D. equinox.
Wheat, barley, and jujube were domesticated in the Indian subcontinent by 9,000 BC, soon followed by sheep and goats. Barley and wheat cultivation, along with the domestication of cattle, primarily sheep and goats; followed in Mehrgarh culture by 8,000–6,000 BC<span>.</span>
The answer is (c) Mountain Ranges. Think of it like when two cars collide head-on, the hoods of the cars bend upward under extreme force. This is the same Idea except with tectonic plates. :)
The cultural importance was that that was where the Egyptians said the dead bodies soul would flow down the river on a boat to get to the afterlife.
