If by taxing you mean Sales Tax, then that is the answer, if not I believe it is
D: Supervising Schools
The answer is option A.
Potassium-Argon method is used to determine the age of artifacts measures the rate of decay in atoms in volcanic rock.
This method can be abbreviated as K-Ar dating, K for potassium and Ar for Argon. This method is used by measuring the product of the radioactive decay of isotope of Potassium and Argon.
There are several reasons why Southeast Asia is considered a crossroads, but the best option from the list would be "<span>(2) A number of trade routes intersect."</span>