$$\text { A long distance phone service charges } \$ 0.35 \text { for the first } 10 \text { minutes and } \$ 0.1 \text { for }$$

Multiple Choice

$$\text { A long distance phone service charges } \$ 0.35 \text { for the first } 10 \text { minutes and } \$ 0.1 \text { for }$$ each additional minute or fraction thereof. Use the greatest integer function to write the cost $C$ of a call in terms of time $t$ (in minutes) .

A) $C = \left\{ \begin{array} { c c } 0.35 & 0 < t \leq 10 \\ 0.35 + 0.1 [ | t - 10 | ] & t > 10 , t \text { is not an integer } \\ 0.35 + 0.1 ( t - 9 ) & t > 10 , t \text { is an integer } \end{array} \right.$
B) $C = \left\{ \begin{array} { c c } 0.35 & 0 < t \leq 10 \\ 0.35 + 0.1 ( t - 10 ) & t > 10 \end{array} \right.$
C) $C = \left\{ \begin{array} { c c } 0.35 & 0 < t \leq 10 \\ 0.35 + 0.1 [ | t - 9 | ] & t > 10 \end{array} \right.$
D) $C = \left\{ \begin{array} { c c } 0.35 & 0 < t \leq 10 \\ 0.35 + 0.1 [ | t - 10 | ] & t > 10 \end{array} \right.$
E) $C = \left\{ \begin{array} { c c } 0.35 & 0 < t \leq 10 \\ 0.35 + 0.1 [ | t - 9 | ] & t > 10 , t \text { is not an integer } \\ 0.35 + 0.1 ( t - 10 ) & t > 10 , t \text { is an integer } \end{array} \right.$