[amp_mcq option1=”02:01″ option2=”01:03″ option3=”02:04″ option4=”None of the above” correct=”option1″]
The correct answer is $\boxed{\text{A. 2:1}}$.
Carbohydrates are made up of carbon, hydrogen, and oxygen atoms. The ratio of hydrogen to oxygen atoms in carbohydrates is always 2:1. This is because carbohydrates are composed of carbon, hydrogen, and oxygen atoms in the ratio $C_xH_2O_y$, where $x$ and $y$ are integers. For example, glucose is a carbohydrate with the chemical formula $C_6H_{12}O_6$. This means that glucose is composed of 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. The ratio of hydrogen to oxygen atoms in glucose is therefore 12:6 = 2:1.
Option B is incorrect because the ratio of hydrogen to oxygen atoms in carbohydrates is not 1:3. Option C is incorrect because the ratio of hydrogen to oxygen atoms in carbohydrates is not 2:4. Option D is incorrect because the ratio of hydrogen to oxygen atoms in carbohydrates is always 2:1.