You need to predict the animal population of an area.

According to the AI-900 official study materials, regression is a type of supervised machine learning used to predict continuous numeric values. Predicting the animal population of an area involves estimating a numeric quantity, which makes regression the appropriate model type.

Microsoft Learn defines regression workloads as predicting real-valued outputs, such as:

Forecasting sales or demand.

Predicting housing prices.

Estimating resource usage or population sizes.

In contrast:

Classification predicts discrete categories (e.g., “cat” or “dog”).

Clustering groups data into similar clusters but doesn’t produce numeric predictions.

Therefore, because the task requires predicting a numerical population size, the verified answer is C. Regression, as per Microsoft’s AI-900 official guidelines.