Final answer:
Stonehenge belongs to the type of megalithic stone known as sarsen. These make up the outermost circle and weigh approximately 25 tons each. Stonehenge also features trilithons, a unique arrangement of two vertical stones with a third stone laid horizontally across the top.
Step-by-step explanation:
To which type of megalithic stone does Stonehenge belong? The correct answer is A. Sarsen. Stonehenge features large megaliths known as sarsen stones in its outermost circle. These sarsen stones are enormous, weighing approximately 25 tons each, and were transported from Marlborough Downs, some twenty-nine kilometers from the construction site. The Stonehenge site also includes smaller bluestones in the inner circle and even larger elements like the Heel Stone.
The Stonehenge monument is renowned for its use of trilithons, which are made up of three stones; two vertical megaliths with one stone laid horizontally across the top in a post-and-lintel system. This type of megalithic stone is a specific feature of Stonehenge, which differentiates it from other types like dolmens or menhirs. The construction of these structures required a high level of planning and coordination, indicative of the Neolithic period where settled life and agriculture required and allowed such massive communal efforts.