General Formula for Monosaccharides

Steps:

• Monosaccharides are simple sugars like fructose, with a backbone of carbon atoms bonded to hydrogen and oxygen.
• Their molecular formula follows a repeating CH₂O unit, reflecting the 2:1 H:O ratio.
• The subscript indicates the number of these units, typically varying for different sugars.
• Standard notation uses "n" as the variable for this count, where n is at least 3.

Why B is correct:

• The general formula for monosaccharides is (CH₂O)_n, as defined in carbohydrate chemistry, where n represents the number of carbon atoms (e.g., n=6 for fructose, C₆H₁₂O₆).

Why the others are wrong:

• A: Subscript 1 limits to a single CH₂O unit, which is formaldehyde, not a sugar.
• C: "m" is not the conventional variable; "n" is standard for carbohydrate formulas.
• D: "k" is unconventional and not used in standard biochemical notation for sugars.

Final answer: B