What happens to lava that emerges from a rift between two pulling oceanic plates?

When lava emerges from a rift between two pulling oceanic plates, it is typically exposed to seawater almost immediately due to its location at mid-ocean ridges. This rapid exposure to water causes the lava to cool quickly, which is why the correct answer focuses on the immediate cooling effect that occurs when lava interacts with seawater. The rapid cooling leads to the formation of basaltic rock, a common result of such volcanic activity.

In contrast, the other options suggest processes that do not occur in this context. Lava cooling slowly underground would pertain to volcanic activity not associated with the direct exposure that occurs at oceanic rifts. The formation of larger igneous rocks typically requires slower cooling processes, allowing for the growth of larger crystals, which does not happen at the rift. Lastly, lava does not evaporate; it cools and solidifies into rock when exposed to cooler temperatures such as seawater.