I finished my high school level studies, i applied to a undergraduate course physiotherpy. But they asked why did you choose this course ?

I finished my high school level studies, i applied  to a undergraduate course physiotherpy. But they asked why did you choose this course ?and i have to write atleast a page. i wrote almost half a page that i took biology inorder to pursue my goals , from child hood onwards it was my passion to become a physiotherapist etc.... I do not know what to write more? Please help me