The correct answer is D. All of these.
Plastics are a large group of synthetic or semi-synthetic organic compounds that are malleable and can be molded into solid objects. They are typically polymers of high molecular weight, and are usually derived from petrochemicals.
The most common elements found in plastics are carbon, hydrogen, oxygen, and nitrogen. Carbon is the main component of plastics, and is responsible for their strength and rigidity. Hydrogen is also a major component of plastics, and helps to make them flexible and lightweight. Oxygen and nitrogen are less common elements in plastics, but they can also play important roles in their properties.
For example, oxygen can be used to create cross-links between polymer chains, which can make plastics stronger and more durable. Nitrogen can be used to create foamed plastics, which are lightweight and have good insulating properties.
The specific elements that are found in a particular plastic will depend on its chemical composition and the manufacturing process used to produce it. However, all plastics will contain at least some carbon, hydrogen, oxygen, and nitrogen.