The answer is: Azure Machine Learning designer (often just called “Designer”).

In Azure Machine Learning Studio, the Designer is the visual, drag‑and‑drop interface you use to author end‑to‑end machine learning pipelines, including regression workflows, by connecting components such as data preparation, training, scoring, and evaluation on a canvas.

Quick Scoop: What this means

  • The drag‑and‑drop tool in Azure ML Studio is Designer (not Notebooks, Automated ML, or Canvas, which is just the visual area inside Designer).
  • With Designer, you can:
    • Load datasets and split them into training and test sets.
    • Drag regression algorithms (like linear regression) onto the canvas.
    • Connect train, score, and evaluate components into a reusable pipeline.

In exam‑style questions, when you see
“in azure machine learning studio, what can you use to author regression machine learning pipelines using a drag-and-drop interface?”
the correct choice is Designer.

TL;DR:
Use Azure Machine Learning Designer in Azure ML Studio to build regression pipelines with a drag‑and‑drop, no‑code interface.

Information gathered from public forums or data available on the internet and portrayed here.