In which of the following geological periods would gymnosperms dominate the landscape?
carboniferous
permian
triassic
eocene (present)

Carboniferous

Explanation:

The Carboniferous was a geological period in which the Earth was much warmer, with the climate being warm and wet in most of it. During this period, the land was covered with dense rain forests. These rainforests were dominated by gymnosperms. Gymnosperms are the plants that have seeds that are not enclosed in an ovary, but instead they are ''naked seeds''. These plants, or rather trees were the ones that actually gave the material for the formation of the large coal deposits.

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.