Frequency distributions can be formed from both discrete and continuous types of data. The correct answer is a) both discrete and continuous.
To explain, a frequency distribution is a summary of how often different values occur within a dataset. Discrete data consists of countable, distinct values, like the number of students in a class, while continuous data involves measurable quantities that can take on any value within a range, like height or temperature.
Both types of data can be represented in a frequency distribution, allowing us to see patterns and distributions effectively. For example, we can list the number of occurrences of each discrete value or group continuous data into ranges (bins) to count how many fall within each range.