; (B) ensure that each clinical observation session— (i) lasts between four and six months; and (ii) to the extent practicable, begins and ends concurrently with one or more academic terms of an institution of higher education; and (C) ensure that the clinical observation sessions provided at a medical center have minimal overlap. (2) Sessions The Secretary shall ensure that the pilot program consists of clinical observation sessions as follows: (A) Each session shall allow for not fewer than five students nor greater than 15 students to participate in the session. (B) Each session shall consist of not fewer than 20 observational hours nor greater than 40 observational hours. (C) A majority of the observational hours shall be spent observing a health professional. The other observational hours shall be spent in a manner that ensures a robust, well-rounded experience that exposes the students to a variety of aspects of medical care and health care administration. (D) Each session shall provide a diverse clinical observation experience. (d) Students (1) Selection The Secretary shall select to participate in the pilot program under subsection (a) students who are— (A) nationals of the United States (as defined in section 101 of the Immigration and Nationality Act ( 8 U.S.C. 1101 )); (B) enrolled in an accredited program of study at an institution of higher education