simplify the complex fraction

4
__
x + 3
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1/x + 3

A. 12x + 4 / yx^2 + 3x
B. 4x / 3x + 9
C. 4x / 3x^2 + 10x +3
D. x^2 + 3x / 12x + 4

C. 4x / 3x^2 + 10x + 3