Correct Answer - C
We have,
`5^(x) = (0.5)^(y) = 1000`
`rArr x = "log"_(5) 1000 " and " y = "log"_(0.5) 1000`
`rArr (1)/(x)-(1)/(y) = "log"_(1000) 5 -"log"_(1000) 0.5`
`rArr (1)/(x)-(1)/(y) = "log"_(1000) ((5)/(0.5)) = "log"_(1000) 10 = "log"_(10^(3)) 10 = (1)/(3)`