When identifying the molecular ion peak, M^+,all of the following must be kept in mind, except: Select one: a. intensities of isotopic peaks M + 1, M + 2 and so forth must be consistent with the proposed formula. b. the peak for the heaviest fragment ion should not correspond to an improbable mass loss from M^+ c. if a fragment ion is known to contain X atoms of element Z, then there must be at least X atoms of element Z in the molecular ion. d. M^+ will be the highest m/z value of any of the "significant" peaks in the spectrum that can not be attributed to isotopes or background. e. M^+ will be at least 70% of the base peak.
