Which of the Following Is Not True About the M+1

Multiple Choice

Which of the following is not true about the M+1 peak?

A) It is one m/z unit higher than the base peak.
B) It is one m/z unit higher than the molecular ion peak.
C) It is one m/z unit higher than the parent ion peak.
D) It occurs because there is more than one naturally occurring isotope of carbon.
E) This means that the number of carbon atoms in a compound can be calculated if the relative abundance of both the M and M+1 peaks is known.