The reaction is missing, so i have attached it.
Answer:
C. An intramolecular aldol condensation
Step-by-step explanation:
From the attached image showing the reaction, we can see that the left hand side of the reaction has 2 carbonyl groups which are the double bonds attached to the oxygen atoms.
Now, on the right hand side, we can see that a six member ring has been formed.
This 6 member ring is produced because one of the carbonyls on the left hand side was deprotonated at the alpha position thereby serving as a nucleophile, which then attacks the carbon in the other carbonyl.
This process is possible because it underwent the processes of deprotonation, intramolecular aldol addition, proton transfer and elimination to yield the right hand side product which is ɑ,β-unsaturated carbonyl compound.
Thus, the correct answer is option C