A local school board has passed a measure requiring principals (provide parents with course materials so as to) improve the quality of their children's education.

The bracket is the underlined part


a) provide parents with course materials so as to
b) to provide parents with course materials so as to
c) provide parents with course materials in order that they
d) to provide parents with course materials so that they can
e) provide parents with course materials and

I came down to b and d .I chose B because d seemed confusing to me ."so that they can choose their children's material.Who is first they and second they is confusing......

let me know .....