5. The function $f(x)=[x]+[2 x]+\left[\frac{5 x}{3}\right]+[3 x]+[4 x], x \in[0,100]$, then the number of elements in the range of $f(x)$ is ().
A. 734
B. 733
C. 701
D. 700
5. $\mathrm{A}$
$f$ has 22 jumps on $[0,3)$, and the jumps of $f$ have a period of 3,
so there are a total of $22 \times 33=726$ values taken on $\left[0\right.$,99). The number of values taken on $[99,100]$ is the same as that on $[0,1\}_{-}^{3} 1$, which is 8, so the total is $726+8=734$ values.