let the first term is 'a'
the second term is (a + d ) = -5 .................(1)
the third term is (a + 2d) = 17 ..................(2)
subtract equation (1) from equation (2)
(a+2d) - (a+d) = 17 -(-5)
a + 2d - a - d = 17 + 5
d = 22
the second term is
a + d = -5
put d = 22
a + 22 = -5
a = -5-22
a = -27
so the answer is first term = -27 that is option C
