Yeast colonies can be considered cylinders of constant height. The number of yeast cells in a colony can be calculated using the linear function $N\left(A\right)=C_{s}A$, where the constant C_s is the cell-surface coefficient, and $A$ is the cross-sectional area of the colony. Debaryomyces fabryi is a yeast commonly found in all types of cheese. Determine the value of C_s for a colony of this yeast with a cross-sectional area of $50$ mm² containing $260\times{10^6}$ yeast cells. Calculate the number of yeast cells in the colony with a cross-sectional area of $100$ mm².

• A. $C_{s}=9.8\times{10^6}$ yeast cells/mm², $N\left(A\right)=23\times{10^6}$ yeast cells
• B. $C_{s}=3.5\times{10^6}$ yeast cells/mm², $N\left(A\right)=73\times{10^6}$ yeast cells
• C. $C_{s}=1.3\times{10^6}$ yeast cells/mm², $N\left(A\right)=130\times{10^6}$ yeast cells
• D. $C_{s}=5.2\times{10^6}$ yeast cells/mm², $N\left(A\right)=520\times{10^6}$ yeast cells

Answer: (D)