Which of the following elements is present in all organic compounds?

• A. $\mathrm{Nitrogen}$
• B. $\mathrm{Sulfur}$
• C. $\mathrm{Phosphorus}$
• D. $\mathrm{Carbon}$

Answer: (D)

Verified step by step guidance

1. Understand the definition of organic compounds: Organic compounds are primarily composed of carbon atoms bonded to hydrogen, oxygen, nitrogen, and other elements.
2. Recall that the key characteristic of organic chemistry is the study of carbon-containing compounds, where carbon forms the backbone of the molecules.
3. Recognize that while elements like nitrogen, sulfur, and phosphorus can be present in some organic compounds, they are not found in all of them.
4. Identify that carbon is the only element that is universally present in all organic compounds, making it the defining element of organic chemistry.
5. Conclude that the element present in all organic compounds is carbon.