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Let $f$ be an everywhere differentiable function such that $\int_{4}^{8}f(2x)dx=6$.

Which of the following is true?

$\int_{8}^{16}f(x)dx=12$

$\int_{8}^{16}f(x)dx=3$

$\int_{2}^{4}f(x)dx=3$

$\int_{2}^{4}f(x)dx=12$