<span>Some of these trade routes had been in use for centuries, but by the beginning of the first century A.D., merchants, diplomats, and travelers could (in theory) cross the ancient world from Britain and Spain in the west to China and Japan in the east</span>
The correct answer is the concrete operational thought. This
is being defined as a way of children to be able to perform concrete operations
by having to reason out in a more logical manner that is applied to specific
examples or concrete examples.
