Student Advisor: One of our exchange students faced multiple arguments

Thanks Vyshak for the great explanation.

Now this makes more sense - effect was not causing the cause.

I was looking at the literal meaning and no looking at what causes the effects and vice versa. Its a tricky question - Initially I thought this is negating the correct answer and will weaken the argument so i skipped it and move to next answer choice and saw all other are irrelevant so had to choose A (which I know will make the argument weaker but I thought thats the best available option).

What is the best way to tackle reverse cause and effect questions like this?

Student Advisor: One of our exchange students faced multiple arguments with her parents over the course of the past year. Not surprisingly, her grade point average (GPA) over the same period showed a steep decline. This is just one example of a general truth: problematic family relationships can cause significant academic difficulties for our students.

The claim by the Student Advisor would be more properly drawn if which of the following were inserted into the argument as an additional premise?

A) Last year, the exchange student reduced the amount of time spent on academic work, resulting in a lower GPA.
B) The decline in the GPA of the exchange student was not the reason for the student's arguments with her parents.
C) School GPA is an accurate measure of a student's intellectual ability.
D) if proper measure are not taken, the decline in the student's academic performance may become irreversible.
E) Fluctuations in academic performance are typical for many students.

Reference: Manhattan Critical Reasoning - fail to understand the correct answer choice explanation.