Answer:
a. continent
Step-by-step explanation:
The major landmasses on the surface of the Earth made out of crustal rock are called continents. The continents are massive land masses. They lie on top of continental tectonic plates which are less dense and higher than the oceanic tectonic plates. In the present there are six continental masses, all with different shape and size. The continental masses that exist in the present are Eurasia, Africa, North America, South America, Australia, and Antarctica.