At 4 Units of Output in Table 21

Multiple Choice

$$\begin{array}{l}\begin{array} { | c | c | } \hline \begin{array} { c } \text { Output } \\\text { (Units per Day) }\end{array} & \begin{array} { c } \text { Total Cost } \\\text { (Dollars per Day) }\end{array} \\\hline 0 & 16 \\\hline 1 & 30 \\\hline 2 & 42 \\\hline 3 & 58 \\\hline 4 & 78 \\\hline\end{array}\\\text { Table 21.4 }\end{array}$$ At 4 units of output in Table 21.4, the total variable cost is

A) $5.00.
B) $20.00.
C) $19.50.
D) $62.00.