Which of the following is an example of gross motor skill development?

Gross motor skills involve the use of large muscle groups to perform significant movements that require strength and coordination. The act of throwing a ball is an excellent example of gross motor skill development because it engages various muscles in the arms, shoulders, and torso. This action requires balance, coordination, and the ability to execute a movement that utilizes large body parts, demonstrating a child's physical growth in these areas.

In contrast, the other options focus on fine motor skills, which involve smaller muscle movements. Using scissors and writing letters require precision and dexterity, using smaller muscles in the hands and fingers. Stacking blocks also involves fine motor skills and hand-eye coordination but on a smaller scale than the whole body movement involved in throwing a ball. Understanding the distinction between gross and fine motor skills is essential for recognizing how various activities contribute to a child's overall physical development.