In terms of majors, business (attract) Answer

the largest numbers - about 20% of the total international student population.

Attracts.

Explanation:

You are supposed to choose the tense of the verb attract and the best option would be present simple. This is because this is happening regularly - every year business is the most popular major among students, which is why present simple tense should be used. Since the word business is singular, you need to add - s to the verb to make it singular attracts.

The other forms would be is attracting (for present continuous), has attracted (for present perfect), and has been attracting (for present perfect continuous), all of which are wrong here.