What are Grignard reagents? Discuss the use of Grignard reagent in the

preparation of 1°-, 2°-and 3°-alcohols​

Grignard reagents are used synthetically to form new carbon–carbon bonds. A Grignard reagent has a very polar carbon–magnesium bond in which the carbon atom has a partial negative charge and the metal a partial positive charge.

Grignard reaction with aldehydes and ketones

To produce a primary alcohol, the Grignard reagent is reacted with formaldehyde. Reacting a Grignard reagent with any other aldehyde will lead to a secondary alcohol. Finally, reacting a Grignard reagent with a ketone will generate a tertiary alcohol.

the answer is definitely c.