According to the Microsoft Azure AI Fundamentals (AI-900) official study guide and Microsoft Learn module “Identify features of regression machine learning”, regression is a type of supervised machine learning used when the target variable (the value you want to predict) is a continuous numeric value.

In this scenario, the task is to predict how many hours of overtime a delivery person will work based on the number of orders received. Both the input (number of orders) and the output (hours of overtime) are numeric variables. Since the goal is to estimate a quantitative value rather than categorize or group data, this is a classic example of a regression problem.

Regression models analyze the relationship between variables to make numerical predictions. For example, the model might learn that each additional 20 orders increases overtime by about two hours. Common algorithms used for regression include linear regression, decision tree regression, and boosted regression models. These models produce outputs such as “expected overtime = 5.6 hours,” which are continuous numeric results.

To contrast with the other options:

Classification is used for predicting categories or labels, such as “overtime required” vs. “no overtime,” or “high-risk” vs. “low-risk.” It deals with discrete outputs rather than continuous numbers.

Clustering is an unsupervised learning approach used to group similar data points based on shared characteristics, such as grouping delivery staff by performance patterns or customer types.

As emphasized in Microsoft’s Responsible AI and Machine Learning Fundamentals learning paths, regression models are ideal for numeric forecasting problems such as predicting sales, revenue, demand, or working hours.

Therefore, the correct answer is: Regression.