The correct answer is b. The code has been arranged such that the if and else statements aren't visually aligned the way that Java interprets these instructions, and it's possible to misinterpret the logic of the statements.

A more clear way to arrange this same code would be

int f = 5;
if (d > 0)
    if (e > 0)
        f = f + 1;
    else
        f = f - 1;
System.out.println(f);

where the else statement, logically connected to the nearest if statement, is lined up beneath it.

To make it even more clear, use curly braces to clearly (and visually) identify the logic:

int f = 5;
if (d > 0)
{
    if (e > 0)
    {
        f = f + 1;
    }
    else
    {
        f = f - 1;
    }
}
System.out.println(f);