b) Participation in a physical education course shall be required of all students a minimum of three days per five day instructional week except when an appropriate medical excuse is submitted (see Section 1.425(d)). A school board may also choose to allow for student exemptions as permitted by Section 27-6 of the School Code (see Section 1.425(e)). If a student nonattendance day is scheduled for a day that would otherwise include physical education or the school building is not open to students, physical education for that day does not need to be made up (e.g., if physical education is regularly scheduled for Monday, Wednesday and Friday, but a teacher inservice is scheduled on a given Monday, physical education for that Monday does not have to be moved to Tuesday or Thursday.) However, school districts shall make every effort to ensure all students have the ability to participate in physical education at least three days per week even when school is in session fewer than five days in a given week.