Special effects in drawing objects refer to the various visual enhancements that can be applied to make the objects more visually appealing and dynamic. These effects can include gradient patterns, shadows, reflections, glows, and more. Among the given options, the one that specifically allows the application of gradient patterns is "Shape Effects."

Shape Effects:
Shape Effects are a set of visual enhancements that can be applied to drawing objects. They allow users to add various effects, such as shadows, reflections, glows, bevels, and gradients, to the selected shape. The "Shape Effects" option can be found in most drawing software, such as Microsoft PowerPoint, Adobe Illustrator, and CorelDRAW.

Gradient Patterns:
A gradient pattern is a gradual transition between two or more colors, creating a smooth blending effect. It can be applied to various drawing objects, such as shapes, text, and images, to add depth and visual interest.

Shape Fill vs. Shape Outline:
While both "Shape Fill" and "Shape Outline" options can enhance the appearance of drawing objects, they do not specifically provide the ability to apply gradient patterns.

- Shape Fill: This option allows users to choose a solid color, texture, picture, or pattern to fill the interior of a shape. However, it does not provide the option to apply gradient patterns.

- Shape Outline: This option allows users to modify the outline or border of a shape by choosing a color, style (such as solid, dashed, or dotted), and thickness. However, it does not provide the option to apply gradient patterns.

All of these:
The correct answer to the question is option 'C' - "Shape Effects." This is because "Shape Effects" is the option that specifically allows users to apply gradient patterns to drawing objects. It provides a wide range of effects, including gradients, which can be customized with different colors, directions, and intensity levels.

By selecting the "Shape Effects" option, users can access a menu or dialog box that allows them to choose the desired effect, such as gradient, and adjust its settings according to their preferences. This enables them to create visually appealing and dynamic drawing objects with gradient patterns.