What are the products of the combustion of a candle in a limited supply of air?

Combustion is a chemical process where a substance reacts rapidly with oxygen, usually producing heat and light. Candle wax is primarily composed of hydrocarbons (compounds of hydrogen and carbon).

• Complete combustion occurs when there is an ample supply of oxygen. For hydrocarbons, this typically produces carbon dioxide ($\text{CO}_2$) and water ($\text{H}_2\text{O}$).
• Incomplete combustion occurs when the supply of oxygen is limited. In this case, not all the carbon is fully oxidized to $\text{CO}_2$. Instead, it can form carbon monoxide ($\text{CO}$) and/or unburnt carbon particles, which are seen as soot. Water ($\text{H}_2\text{O}$) is still typically formed.

The question specifies a "limited supply of air," which means incomplete combustion will occur. Therefore, the products will include soot and carbon monoxide ($\text{CO}$), along with water. However, the options provided combine these products differently.

Let's analyze the options:
A. Water and $\text{CO}_2$: This represents complete combustion.
B. Soot and $\text{CO}$: These are characteristic products of incomplete combustion.
C. Soot and $\text{CO}_2$: While soot indicates incomplete combustion, $\text{CO}_2$ is a product of complete combustion. It's possible to have a mix, but $\text{CO}$ is more indicative of limited oxygen than $\text{CO}_2$ in this context.
D. Water and $\text{CO}$: $\text{CO}$ is a product of incomplete combustion, and water is always formed. However, incomplete combustion also typically produces soot.

Considering the most characteristic products of incomplete combustion of a hydrocarbon, the formation of soot (unburnt carbon) and carbon monoxide ($\text{CO}$) are key indicators of a limited oxygen supply. While water is also formed, option B specifically highlights the products that distinguish incomplete combustion from complete combustion.

The most accurate answer describing the products under a limited supply of air is the formation of soot and carbon monoxide.

The final answer is $\boxed{\text{B}}$.