15. Chloe randomly picks a real number from the interval $[0,2017]$, and Laurent randomly picks a real number from the interval $[0,4034]$. The probability that the number Laurent picks is greater than the number Chloe picks is ( ).
(A) $\frac{1}{2}$
(B) $\frac{2}{3}$
(C) $\frac{3}{4}$
(D) $\frac{5}{6}$
(E) $\frac{7}{8}$
15. C.

Let Chloe take a real number $x(x \in[0,2017])$, and Laurent take a real number $y(y \in[0,4034])$. As shown in Figure 3, using geometric probability, we get
$$
\begin{aligned}
p & =\frac{\{(x, y) \mid 0 \leqslant x \leqslant 2017,0 \leqslant y \leqslant 4034, y>x\}}{\{(x, y) \mid 0 \leqslant x \leqslant 2017,0 \leqslant y \leqslant 4034\}} \\
& =\frac{3}{4} .
\end{aligned}
$$