Oxidation of secondary alcohol to ketone followed by Grignard addition Steps: - Acidified K2Cr2O7 under reflux with excess oxidizes primary alcohols to carboxylic acids, secondary to ketones, and alkanes not at all. - Compound Y must be a ketone to undergo nucleophilic addition with a Grignard reagent (compound Z) to form a tertiary alcohol (product, also called Z here due to naming error). - For the product Mr = 172, the ketone Y from secondary alcohol X must add an alkyl group of Mr 99 (C7H15) to reach C11H24O (172). - Option D gives butan-2-one (Mr 72), + C7H15 (99) +1 H = 172; other secondary (B) gives larger ketone (114), requiring smaller alkyl (57) not specified. Why D is correct: - D is a secondary alcohol oxidized to butan-2-one, which follows the Grignard addition formula: Mr(tertiary alcohol) = Mr(ketone) + Mr(alkyl) + 1 = 72 + 99 + 1 = 172. Why the others are wrong: - A is an alkane, not oxidized to a reactive Y. - B is secondary but gives heptan-4-one (Mr 114); Grignard addition requires …