Which pictorial representation shows depth true to size and at any angle?

The correct choice is the option that defines an oblique sketch, which is characterized by its ability to convey depth accurately while allowing for various angles. In an oblique sketch, the front view is presented in true shape and size, while depth can be represented at an angle, typically at 45 degrees. This technique effectively maintains the proportions of the depth, ensuring a clear and recognizable depiction of the object being illustrated.

This versatility makes the oblique sketch particularly useful in engineering and design, as it enables the viewer to understand the three-dimensional aspects of the object without distortion, unlike other types of pictorial representations. While the other options also represent three-dimensional objects, they do not specifically meet the criteria of showing depth accurately at any angle, which is a hallmark of the oblique sketch.