Estimate the Value of the Quantity $4.7 \mathrm { mg }$

Estimate the value of the quantity.
-The table gives dye concentrations for a cardiac-output determination. The amount of dye injected was $4.7 \mathrm { mg }$ . Plot the data and connect the data points with a smooth curve. Find the area under the curve using rectangles. Use this area to estimate the cardiac output.
$\begin{array}{c|c}\begin{array}{c}\text { Seconds } \\\text { after } \\\text { injection }\end{array} & \begin{array}{c}\text { Dye Conc. } \\\text { (adjusted for } \\\text { recirculation) }\end{array} \\\hline 0 & 0 \\2 & 0.5 \\4 & 1.2 \\6 & 2.3 \\8 & 3.8 \\10 & 4.6 \\12 & 4.5 \\14 & 3.2 \\16 & 1.8 \\18 & 0.5 \\20 & 0\end{array}$

A) $12.9 \mathrm {~L} / \mathrm { min }$
B) $6.4 \mathrm {~L} / \mathrm { min }$
C) $279.6 \mathrm {~L} / \mathrm { min }$
D) $0.1 \mathrm {~L} / \mathrm { min }$