Consider the Following Cost Data for the Cost Object, Number

Consider the following cost data for the cost object, number of machine setups. Each set of costs (A, B, and C) is from a different type of manufacturing operation and represents the cost behaviour for the cost of that company's machine setups. $\begin{array}{c}\begin{array}{c}\text {Number of}\\\underline{\text { Machine Setups}}\\0 \\10 \\20 \\30 \\40 \\50\end{array}\begin{array}{c}\\\underline{\text { Cost A }} \\\$ 0 \\20 \\40 \\60 \\80 \\100\end{array}\begin{array}{c}\\\underline{\text { Cost B }} \\ \$ 80 \\79 \\82 \\78 \\81 \\79\end{array}\begin{array}{c}\\\underline{\text { Cost C} } \\\$ 5 \\37 \\66 \\91 \\123 \\154 \end{array}\end{array}$
Cost A is best described as:

A) Variable
B) Fixed
C) Mixed
D) Direct