Which statement is an example of an objective sentence?

C. would be the correct objective option for this question.  Options A, B, and D are all subjective.  Meaning they are of an opinion.  Mr. Gettridge being 82 when hurricane Katrina destroyed his home was the only option that was purely a fact.  

For reference, an objective point of view is one that is not at all affected by opinion or emotions.  Objective points of view are purely based on fact.  And, subjective is the opposite of objective.    

the correct answer is a. how to make proposal that works.

indeed, the register is quite formal and the tone is especially objective as it avoids the use of the first and second person singular (i, you) and opts instead for the third person plural which is more impersonal and focuses on the data and the argument that is being developed by the author. the formality adds the impression of respectability to the work and the impersonality adds objectivity to it.

the answer is the second one.