What type of igneous rock has a fine-grained texture and is typically dark in color?

The correct choice is basalt, which is an igneous rock characterized by its fine-grained texture and typically darker coloration. Basalt forms from the rapid cooling of lava that is rich in iron and magnesium, which contributes to its dark hue. It is commonly found in volcanic regions and represents a dominant rock type in oceanic crust.

Basalt's fine-grained texture results from the quick cooling process that does not allow large crystals to form, making the mineral grains generally too small to be seen with the naked eye. This contrasts with granite and diorite, which are coarse-grained due to slower cooling processes that allow larger crystals to develop. Rhyolite, while it can also have a fine-grained texture, is usually lighter in color because it is more silica-rich compared to basalt. Thus, basalt stands out as the igneous rock with the specified characteristics of being fine-grained and typically dark in color.