I am stupidT.T

I just finish my Math Quiz 2 at Exam Hall
Unfortunately, My seat is in front of Air-Con
I felt very cold and a bit hard to concentrate my math question
The calm air let my eye so pain
Well,I hopefully and trust can get full mark at this quiz
But after this test, I know impossible to get it
Stupid me, poor Girl!
The Last question is x^4 In(x) + x^3
(A) 4x^2 + 3 x^2
(D) x^3+3x^2+4x^3 In(x)


First times I write answer (D), after I recheck again, I turn to write (A)
This both answer I also can calculated it! But why after I need change the answer!?
After the test I keep on ask friend what the answer, the answer is (D)
I cannot trust it, after I research Logarithmic question from internet...=.= Sorry,I am wrong! =(
Really damn hate myself, because my Math no perfect just will change answer and the most important is I am no enough confident! Last min I just prepared for this test, I understand this is my fault!
Sad sad, Loss this mark then cannot get Full Mark jor!T.T
This really Spoil My dream! The final exam I should study hard and increase my confident!