Which of the following correctly lists the three main types of carbohydrates?

• A. Monosaccharides, disaccharides, and polysaccharides
• B. Aldoses, ketoses, and pentoses
• C. Starch, cellulose, and glycogen
• D. Glucose, fructose, and galactose

Answer: (A)

Verified step by step guidance

1. Understand the question: The problem is asking for the three main types of carbohydrates. Carbohydrates are classified based on their structure and complexity.
2. Step 1: Recall the classification of carbohydrates. Carbohydrates are broadly divided into three main types: monosaccharides (single sugar units), disaccharides (two sugar units linked together), and polysaccharides (long chains of sugar units).
3. Step 2: Analyze the options provided. The first option lists monosaccharides, disaccharides, and polysaccharides, which align with the structural classification of carbohydrates. The other options describe specific subcategories or examples of carbohydrates.
4. Step 3: Clarify why the other options are incorrect. For example, 'Aldoses, ketoses, and pentoses' refer to specific types of monosaccharides based on functional groups and carbon chain length. 'Starch, cellulose, and glycogen' are examples of polysaccharides. 'Glucose, fructose, and galactose' are examples of monosaccharides.
5. Step 4: Conclude that the correct answer is the first option: Monosaccharides, disaccharides, and polysaccharides, as these represent the three main types of carbohydrates based on their structural complexity.