A box contains 23 electric bulbs, out of which 4 are defective. Two bulbs are chosen at random from this box. The probability that at least one of these is defective is	Choose the correct choice from the following answers:
A) 4 / 19
B) 7 / 19
C) 12 / 37
D) 21 / 95
E) none

Rationale: solution p ( none is defective ) = 19 c 2 / 23 c 2 = 25 / 37 . p ( at least one is defective ) = ( 1 - 25 / 37 ) = 12 / 37 . answer c
Answer: C