Rymore Company Would Like to Classify the Following Costs According

Rymore Company would like to classify the following costs according to their cost behaviour:
$\begin{array}{|l|r|r|}\hline & \text { July } & \text { August } \\\hline \text { Sales in Units } & 1,500 & 1,600 \\\hline \text { Cost A } & \$ 35,000 & \$ 36,000 \\\hline \text { Cost B } & 16,000 & 16,000 \\\hline \text { Cost C } & 67,500 & 72,000 \\\hline\end{array}$


-Which of the following classifications best describes the behaviour of Cost A?

A) Mixed.
B) Variable.
C) Fixed.
D) Opportunity cost.