What is a key characteristic of pyrotechnics?

A key characteristic of pyrotechnics is that it includes controlled chemical reactions for varied effects. This characteristic is fundamental to the nature of pyrotechnics, as it encompasses a variety of applications, including fireworks displays, special effects in film, and other forms of theatrical presentations. The controlled chemical reactions are what produce the visual and auditory effects that are characteristic of pyrotechnics, such as the vibrant colors and sounds associated with fireworks.

In pyrotechnics, different chemical compositions can be used to achieve specific effects, such as bright colors, glittering effects, or loud bangs, which are essential for the entertainment value of displays. This control over chemical reactions allows for creativity and versatility in designing pyrotechnic displays.

Other options such as involving only sound effects, requiring high-altitude launches, or utilizing only handheld devices do not capture the full scope of what pyrotechnics entails. Instead, they misrepresent the complexity and variety of pyrotechnic applications, focusing too narrowly on specific aspects rather than the broader characteristic of chemical reactions that define the field.