A confusing choice

[Mr. Jan]

A confusing choice in third official booklet: All the students will agree / agreed on the school new rules

I think that people will discuss this differently.
Test makers must comprehend that students are not scientists but they are just learners of a second language. How will the education process be modified as they are always saying?

[Mr. Magdi Shalabi Nassar]

I think both answers are not sufficient. The best answer will be "have agreed" as they have done so at an unknown time in the past