Which of the following is a bondline structure of glycerol?

Step-by-step solution

Glycerol is propane-1,2,3-triol , a three-carbon chain with hydroxyl groups at each position: HOCH₂ CH(OH)CH₂ OH. Option A contains a double bond and three hydroxyl groups—unsaturated, not glycerol. Option B also contains a double bond and three hydroxyl groups—unsaturated, not glycerol. Option C shows a four-carbon chain—incorrect carbon count. Option D correctly depicts a three-carbon chain with hydroxyl groups at positions 1, 2, and 3. The structure corresponds to HOCH₂ CH(OH)CH₂ OH.