Match the following:

List-$I$ (Pollutant concentration limit in water)	List-$II$ (Effect)
$A. Pb > 50 \ ppb$	$I. \text{Liver damage}$
$B. SO_4^{2-} > 500 \ ppm$	$II. \text{Laxative effect}$
$C. NO_3^{-} > 50 \ ppm$	$III. \text{Blue baby syndrome}$
$D. F^{-} > 2 \ ppm$	$IV. \text{Brown mottling of teeth}$

The correct answer is

• A
  $A-I, B-II, C-III, D-IV$
• B
  $A-I, B-II, C-IV, D-III$
• C
  $A-II, B-I, C-III, D-IV$
• D
  $A-III, B-II, C-I, D-IV$