Without any calculations it's evident it can't be neither B (both numbers are even, so they're divisible by 2) nor C (the numbers end in 0 and 5, so they're divisible by 5).
A.
[tex]57=3\cdot19\\
96=2^5\cdot3[/tex]
Both numbers have a factor of 3, so they're not relatively prime.
That means it must be D. But, let's check it.
[tex]143=11\cdot13\\
323=17\cdot19[/tex]
Indeed, those two numbers are relatively prime.
