Cho

Câu hỏi: Cho ${\int }_0^1(1+3x) f\text{'}\left(x\right) dx = 2019$; 4f(1)-f(0) =2020. Tính ${\int }_0^{\frac{1}{3}}f\left(3x\right)dx$

A. $\frac{1}{9}$

B. 3

C. $\frac{1}{3}$ 

D. 1