Which of the following operations can a drilling machine not perform?

A drilling machine is primarily designed for creating round holes in materials. While it is versatile and can perform several operations, some tasks fall outside its typical capabilities.

Reaming, spot facing, and tapping are all operations that can be effectively performed on a drilling machine. Reaming enhances the existing hole's accuracy and finishes it to precise dimensions. Spot facing is a technique used to create a flat surface around a hole to accommodate a nut or bolt head—something a drilling machine can achieve with the right setup. Tapping, which involves cutting threads into a pre-drilled hole, can also be accomplished on a drilling machine using the appropriate tapping attachment.

In contrast, broaching is a machining process used to create complex shapes and profiles that require a series of cutting teeth on a specialized tool called a broach. A drilling machine typically lacks the necessary structure and tool support to perform broaching effectively. This process requires specific machinery, like a broaching machine, to handle the linear motion and cutting forces involved in producing the desired shape.

Thus, the inability of a drilling machine to perform broaching makes it the correct answer.