(b) an incarcerated individual of any public institution or any
incorporated private institution, or
(c) if a child under the age of twenty-one years, in a boarding home
under the care of an authorized agency, or
(d) residing on any military reservation.
If, however, the periods of residence immediately prior and subsequent
to the period specified in a, b, c, or d, shall together equal the
required period of residence, such person shall be deemed to have had
the required continuous residence.