Which tool would you select if you wanted to texture the inside faces of an object?

The option to choose when texturing the inside faces of an object is to flip face normals. In 3D modeling, normals represent the direction that a surface is facing, and they are crucial for how textures and lighting are applied to a mesh. When you want to texture the inside of an object, you must ensure that the face normals of those internal surfaces are facing outward; otherwise, the textures will not be displayed correctly because they may be culled or ignored by the rendering engine.

By flipping the face normals, you effectively make the internal surfaces visible and able to receive texture information. This is particularly important in scenarios where the inside of a mesh needs to be rendered or textured, such as in a hollow object or when working on details that should be seen from inside.

Other tools, such as extrude and push faces, are focused on altering the geometry of the object rather than on orientation or texturing specifically. Surface shaders deal with shading methods and material appearances but do not directly pertain to controlling which surfaces are selectable for texturing. Hence, flipping face normals is the most relevant choice for achieving the desired result of texturing the inside faces.