Answer: C — 52 is the mode of the data.
Since the maximum number of students obtained 52 marks, 52 is the observation that occurs most frequently, which is the mode.
Mode is defined as the value that appears most often in a data set. "Maximum number of students obtained 52 marks" directly means 52 has the highest frequency — that is the definition of mode. Mean requires calculation of average; median is the middle value; range is the difference between highest and lowest values.