I'd like to have a TikZ figure in a `parts`-environment, but the figure appears above part (a) instead of below. How can I get the picture to follow the (a)?
Thanks for your help!

```
\documentclass[addpoints,12pt]{exam}

\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{amsmath, amssymb, amsmath}
\usepackage{pgf,tikz}
\usetikzlibrary{arrows}
\usepackage{siunitx}

\begin{document}

\begin{questions}
    \question
        Find $x\in \mathbb{Q}$.
        \begin{parts}
            \part 
                \begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1.0cm,y=1.0cm]
                        \clip(-2.0992637227845954,-1.7878880377249167) rectangle (7.801609010358657,5.493825659968799);
                       \draw [domain=-2.0992637227845954:7.801609010358657] plot(\x,{(--6.6108--1.8599999999999999*\x)/3.96});
                       \draw [domain=-2.0992637227845954:7.801609010358657] plot(\x,{(--3.4032-0.72*\x)/4.2});
                       \draw [domain=-2.0992637227845954:7.801609010358657] plot(\x,{(--7.455599999999999-2.58*\x)/0.23999999999999977});
                       \draw (2.75,1.5) node {\rotatebox{60}{$\parallel$}};
                       \draw [domain=-2.0992637227845954:7.801609010358657] plot(\x,{(--13.01549181869475-2.58*\x)/0.23999999999999977});
                       \draw (4.85,1.8) node {\rotatebox{60}{$\parallel$}};
                       \draw (3,3.15) node[anchor=north west] {$\SI{1.5}{cm}$};
                       \draw (5.114713103302678,2.140850515449367) node[anchor=north west] {$x$};
                       \draw (0.28281626204234456,1.9263504220289323) node[anchor=north west] {$\SI{3}{cm}$};
                   \end{tikzpicture}
               \part
        \end{parts} 
\end{questions}

\end{document}

```

Here's a picture:

![enter image description here](https://i.stack.imgur.com/ltiSs.png)