Which of the following expressions shows that rational numbers are associative under multiplication.
Options:
(a) `2/3xx((-6)/7xx3/5)=(2/3xx(-6)/7)xx3/5`
(b) `2/3xx((-6)/7xx3/5)=2/3xx(3/5xx(-6)/7)`
(c) `2/3xx((-6)/7xx3/5)=(3/5xx2/3)xx(-6)/7`
(d) `(2/3xx(-6)/7)xx3/5=((-6)/7xx2/3)xx3/5`