As used in the Public School Code:

A. “elementary school” means a public school providing instruction for grades kindergarten through eight, unless there is a junior high school program approved by the state board [department], in which case it means a public school providing instruction for grades kindergarten through six;

B. “secondary school” means a public school providing instruction for grades nine through twelve, unless there is a junior high school program approved by the state board [department], in which case it means a public school providing instruction for grades seven through twelve;

C. “junior high school” means a public school providing a junior high school program approved by the state board [department] for grades seven through nine, or for grades seven and eight; and

D. “high school” means a public school providing instruction for any of the grades nine through twelve, unless there is a junior high school program approved by the state board [department] for grades seven through nine, in which case it means a public school providing instruction for any of the grades ten through twelve.