Consider the following class definition.

$```$

public class FishTank

$\{$

private double numGallons;

private boolean saltWater;

public FishTank$($double gals, boolean sw$)$

$\{$

numGallons $=$ gals;

saltWater $=$ sw;

$\}$

public double getNumGallons$()$

$\{$

return numGallons;

$\}$

public boolean isSaltWater$()$

$\{$

if $($saltWater$)$

$\{$

return "Salt Water";

$\}$

else

$\{$

return "Fresh Water";

$\}$

$\}$

$\}$

$```$

Which of the following best explains the reason why the class will not compile?