Answer
Option e.
A NET negative charge.
Work Step by Step
The electric field lines flowing out of the box create a positive flux and those lines going into the box create a negative flux.
Summing all of these results in having 4 inward electric field lines and 2 outward electric field lines. Therefore, the overall electric flux of the box is negative.
But is it a $ $ $net$ $ $ negative charge or just a negative charge? The difference here is that a $ $ $net$ $ $ negative charge means that overall, all of the charges in the box sum to a negative number. Having just a negative charge means that there is ONLY a source negative charge. Since we cannot see what is inside the box–there may be both negative and positive charges in the box but still having an overall negative charge–we must say that there is a $ $ $net$ $ $ negative charge.
Option e. is correct, a net negative charge.
