Which of the Following Cases Require the Mean of a Sample

Multiple Choice

Which of the following cases require the mean of a sample to be calculated using the formula = $\bar{x}=\frac{\sum_{i=1}^{N} f_{i} x_{i}}{N}$
?

A) the sample has no mode value
B) there is direct access to the raw data
C) sample data are grouped in a frequency distribution
D) the coefficient of skewness is 1 or less than -1