An Analyst Performs and External Standard Calibration for Fentanyl and Obtains

An analyst performs and external standard calibration for fentanyl and obtains the following data points (concentration in ppb, area counts) :
20.0, 9599
50.0, 21456
100.0, 45326
250.0, 102391
500.0, 210561
Using the resulting calibration curve, calculate the concentration of fentanyl (ppb) in a sample that generates area counts of 48722 (4 digits) .

A) 114.0
B) 39.80
C) 386.0
D) 59.80
E) none of the above