Krishna is $56$ years old; he has contributed to the CPP without interruption for over $30$ years. W crossing the street, Krishna was struck by a bus and seriously injured. He is currently hospitaliz life support and his doctors have informed Krishna's family that it is uncertain as to whether he from his coma. Assuming at the time of his accident, Krishna was entitled to a CPP retirement be $$660,$ the flat$-$rate disability amount is $$496\mathrm{.}36$ per month and the maximum monthly disability $$1362\mathrm{.}30,$ how much of a disability benefit will Krishna receive under the CPP$?$

a$)$ $$0$

b$)$ $$865\mathrm{.}94$

c$)$ $$991\mathrm{.}36$

d$)$ $$1156\mathrm{.}36$