Measures of central tendency are used in statistics to represent the central or typical value of a set of data. There are three main measures of central tendency: mean, median, and mode. Let's discuss each of them in detail.

Mean:
The mean is the most commonly used measure of central tendency. It is calculated by adding up all the values in a set of data and then dividing the sum by the number of values. The formula for mean is:

Mean = (sum of values) / (number of values)

Median:
The median is the middle value in a set of data when the values are arranged in order. It is not affected by extreme values or outliers that can skew the mean. To find the median, the data must first be arranged in order from smallest to largest. If there are an odd number of values, the median is the middle value. If there are an even number of values, the median is the average of the two middle values.

Mode:
The mode is the value that appears most frequently in a set of data. It is useful for finding the most common value or category in a dataset. In some cases, there may be more than one mode, or no mode at all.

Conclusion:
Thus, the correct answer to the question is option B, which states that there are three measures of central tendency: mean, median, and mode. It is important to choose the appropriate measure of central tendency based on the type of data and the research question being asked.