an example of back formation is
A)persuasive
B}Conciliator
C}Sensitize
D}Escalate
None of those choices seem to meet this explanation of back formation.
http://grammar.about.com/od/ab/g/backformterm.htm
An example of back formation is:
C) Sensitize
Back formation is a linguistic process where a new word is formed by removing an imagined or misinterpreted affix from an existing word. In this case, the word "sensitize" was formed by removing the suffix "-ation" from the noun "sensation."
To identify a back formation, you can start by looking for any irregularities in the word. In this case, the word "sensitize" doesn't have a corresponding noun form with the suffix "-ation." By recognizing this irregularity, you can infer that "sensitize" is a back formation.
Note that back formations are not always simple or intuitive to identify, as they require knowledge of the original word and its affixes. It can be helpful to consult dictionaries or linguistic resources for further confirmation and examples.