This is all the information I have. I am not sure how to use MarvinSketch. If you do not know then please just provide me with the missing reagent and I will figure out the SMILES string by myself. Please just help me find the missing reagent. Thank you so much for the help :)

QUESTION 2 What is the missing reagent that would be used to form the product? ? OH Submit your answer as a SMILES string. Matching answers will be generated with Marvin Sketch, and are all neutral. If your structure is an aldehyde, include the aldehyde hydrogen with your structure. If your structure is an ester, use an ethyl ester. QUESTION 3 What is the missing reagent that would be used to form the product? ? H Submit your answer as a SMILES string. Matching answers will be generated with Marvin Sketch, and are all neutral. If your structure is an aldehyde, include the aldehyde hydrogen with your structure. If your structure is an ester, use an ethyl ester