Why does hosa require students join through a local chapter instead of joining as individuals?
o hosa activities are so closely connected with the school curriculum.
hosa membership would be too expensive for individuals to afford.
all hosa activities are structured as team competitions.
hosa members must take frequent tests.

It's because the activities of HOSA are so closely linked to the curriculum of the school.

Explanation:

HOSA is a US-recognized international student association. Education Department and the ACTE Health Science Education Department (HSE). The double task of HOSA is to encourage career opportunities for the health sector and to boost the quality of good health care for all.

Activities during HOSA Week are planned to provide school and community services, facilitate incentives and convey the wellness community's gratitude. The HOSA goal is to enable HOSA-Future Health Experts through training, partnership and expertise become community leaders in the public health sector.

i think it is the third one.