OG详解-OG4 数学1 Q1

Choice B is correct. The height of each bar in the bar graph given represents the number of students that voted for the activity specified at the bottom of the bar. The bar for activity 3 has a height that is between 35 and 40. In other words, the number of students that chose activity 3 is between 35 students and 40 students. Of the given choices,  39 is the only value between 35 and 40. Therefore, 39 students chose activity 3.
Choice A is incorrect and may result from conceptual errors. Choice C is incorrect. This is the number of students that chose activity 5, not activity  3. Choice D is incorrect and may result from conceptual errors.