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

1503 : 3004 :: 871 : 1740 :: ? : 142

72

Pattern followed is :

2nd term =( 1st term ) × 2 - 2

1503 : 3004

2nd term =( 1503 ) × 2 - 2= 3006 - 2 = 3004

& 871 : 1740 

2nd term =( 871 ) × 2 - 2= 1742 - 2 = 1740

Similarly ,

? : 142

2nd term =( 1st term ) × 2 - 2

`142 = ( 1st term ) × 2 - 2 

( 1st term ) × 2 = 144

1st term = 72

72 is correct answer .