Answer:
D. All of the above
Step-by-step explanation:
An aldehyde and alcohol can react to form Hemiacetals or Hemiketals depending on the nature of the reaction. In situations where the alcohol is only partially reacted with the aldehyde, a Hemiacetal is formed. If the alcohol is fully reacted with the aldehyde, a Hemiketal is formed. Semiketal isn't a term used for describing a chemical reaction between an alcohol and an aldehyde.
Therefore, the correct answer is (D) All of the above since the reaction can form either Hemiacetals or Hemiketals.