By the age of three, most children can accomplish which of the following tasks?

By the age of three, most children are at a developmental stage where they can engage in activities that involve simple problem-solving and fine motor skills. Completing simple puzzles is a typical accomplishment for children in this age range, as they begin to understand how to fit shapes together and recognize patterns. Additionally, drawing clear lines represents their growing control over their hand movements and an emerging understanding of representation in art.

At three years old, children's drawing reflects their developing fine motor skills, and while they may not yet be perfect, they can create basic shapes and lines. This ability to perform simple tasks and create drawings demonstrates the typical milestones of artistic and cognitive development for preschool-aged children.

The other options suggest tasks that are generally beyond the capabilities of most three-year-olds. Copying complex shapes, drawing intricate human figures, or writing names and letters requires more advanced motor skills and cognitive processes that typically develop later, around ages four to six.