Step 1: Understanding the Concept:
In statistics, variables are classified based on the nature of values they can take.
Step 2: Detailed Explanation:
Discrete variables can only take specific, isolated values (usually integers resulting from counting, such as the number of leaves or number of insects).
Continuous variables can assume any real value within a given range.
Measurements such as weight, height, and length fall into this category because they are obtained by measuring rather than counting, and can be represented in decimals (e.g., \(1.56\text{ m}\), \(45.8\text{ kg}\)).
Step 3: Final Answer:
Therefore, these are known as continuous variables, which is option (C).