OG详解-OG10 文法 Q10

Choice B is the best answer. “Next” logically signals that the action described in this sentence—Konkoly recording participants’ eye movements—is the next step in Konkoly’s experiment. 
Choice A is incorrect because “specifically” illogically signals that this sentence specifies or elaborates on an aspect of the action described in the previous sentence. Instead, it describes the next step in Konkoly’s experiment. Choice C is incorrect because “for instance” illogically signals that the action described in this sentence is an example of the action described in the previous sentence. Instead, it is the next step in Konkoly’s experiment. Choice D is incorrect because “in sum” illogically signals that this sentence summarizes or concludes the action described in the previous sentence. Instead, it describes the next step in Konkoly’s experiment.