The document discusses multiple chemistry questions and their answers: 1. The answer for which reagents can be used to carry out a substitution reaction is both option A and D. 2. The necessary reagents to convert a bromide to a carboxylic acid are magnesium followed by carbon dioxide and water, and sodium cyanide followed by water and heat. 3. The reaction sequence provided would result in a tertiary alkyl bromide being converted to the corresponding tertiary alcohol.