Which Are TRUE Statements Regarding Internal Standards

Multiple Choice

Which are TRUE statements regarding internal standards?
I The response factor is calculated by using a mixture containing known amounts of analyte and internal standard and by using detector response to the analyte and the internal standard.
II Internal standards are useful where instrument response or quantity of sample analyzed varies over time.
III Detector response is inversely proportional to concentration.
IV Detector response to analyte and internal standard is assumed to be constant over a range of concentrations.

A) I,II,and III
B) II,III,and IV
C) I and II
D) I and III
E) I,II,and IV