Choice B is the best answer because the transitional phrase “For instance” logically indicates that what follows provides an example related to the previous sentence. “Representatives from the local public health department” is an example of the kinds of people with whom transportation planners work.
Choice A is not the best answer because the transitional word “Next” indicates sequence, which is not logical given that what follows provides an example related to the previous sentence.
Choice C is not the best answer because the transitional word “Furthermore” indicates addition, which is not logical given that what follows provides an example related to the previous sentence.
Choice D is not the best answer because the transitional word “Similarly” indicates comparison or likeness, which is not logical given that what follows provides an example related to the previous sentence.