事实上，国际性测试是衡量学校质量的一种好途径。

As a matter of fact, international tests are a good way to measure the quality of schools.
B. As a matter of fact, international tests is a good way to measure the quality of schools.
C. As a matter of fact, international tests is a better way to measure the quality of schools.
D. As a matter of fact, international tests are a better way to measure the quantity of schools.