Which of the following compounds will give racemic mixture by `S_(N^(1))` reaction?

Which of the following compound will be most reactive toward S_(N)^(1) reaction?

Which of the following compounds will give racemic mixture on nucleophillic substitution by OH^(-) ion?

Which of the following compounds will give racemic mixture on nucleophillic substitution by OH^(-) ion?

Which of the following compounds will give S_(N^(1)) reaction?

Since, Grignard reagents resemble carbanion, so they are strong nucleophile and strong base. Their most useful nucleophilic reaction is addition to carbonyl group. Which of the following compounds give racemic mixture on reaction with H_(3)C-MgBr ?