Select the option that is related to the fourth number in the same way as the first number is related to the second number and fifth number is related to sixth number.

11 : 1000 :: ? : 1728 :: 9 : 512

13

Pattern followed is : X : (X-1)³

11 : 1000 ⇒ 11 : (11-1)³ ⇒ 11 : 10³ ⇒ 11 : 1000

same as

9 : 512 ⇒ 9 : (9 - 1)³ ⇒ 9 : 8³ ⇒ 9 : 512

Similarly ,

x : 1728 ⇒ x : 12³  ⇒ x : (13 - 1)³ ⇒ x = 13

13 , is correct answer .