Let $y=t$ Be One Part of a Parametric Equation $x$ As a Function Of

Let $y=t$ be one part of a parametric equation. Which of the following formulas for $x$ as a function of $t$ on $0 \leq t \leq 6$ completes the parameterization of the graph of a straight line from $(0,0)$ to $(1,1)$ , and then continuing from $(1,1)$ in a straight line to $(0,6)$ ?

A) $x=\left\{\begin{array}{cc}t & 0 \leq t \leq 1 \\ 6-t & 1 \leq t \leq 6\end{array}\right.$
B) $x=\left\{\begin{array}{cc}6-t & 0 \leq t \leq 1 \\ t & 1 \leq t \leq 6\end{array}\right.$
C) $x= \begin{cases}t & 0 \leq t \leq 1 \\ 6 & 1 \leq t \leq 6\end{cases}$
D) $x=\left\{\begin{array}{cc}1-t & 0 \leq t \leq 1 \\ 6 & 1 \leq t \leq 6\end{array}\right.$