such a loan shall be repayable in equal or graduated periodic installments (with the right of the borrower to accelerate repayment) over the ten-year period which begins nine months after the student ceases to pursue a full-time or half-time course of study at a school of nursing, excluding from such 10-year period all (A) periods (up to three years) of (i) active duty performed by the borrower as a member of a uniformed service, or (ii) service as a volunteer under the Peace Corps Act [
22 U.S.C. 2501 et seq.], (B) periods (up to ten years) during which the borrower is pursuing a full-time or half-time course of study at a collegiate school of nursing leading to baccalaureate degree in nursing or an equivalent degree, or to graduate degree in nursing, or is otherwise pursuing advanced professional training in nursing (or training to be a nurse anesthetist), and (C) such additional periods under the terms of paragraph (8) of this subsection;