Answer:b. small crystals and fine texture
Explanation: Generally, igneous rocks are formed from the solidification of moltenmagma . Molten magma are usually semi liquid that originates from the interior of the earth. The location or environment where the magma solidifies determine the kind of igneous rock that is formed. If the magma solidifies below the earth crust it will result to an intrusive igneous rock which have a coarse texture due to the slow rate of solidification. But if magma creeps or erupt to the surface of the earth crust as lava, the solidification process becomes rapid to form an extrusive igneous rock.Lava pouring out of the crust at a vent or fissure on the ocean floor are more expose to cooler temperature, water and air . This result to rapid cooling and more faster crystallizing process to form more fine grain and small crystals. Example of this extrusive types of igneous rocks is Basalt. The picture below are examples of extrusive igneous rocks . Notice their small crystal .