A disaccharide X cannot be oxidised by bromine water. The acid hydrolysis of X leads to a laevorotatory…

A and D cannot be oxidised by bromine water as they do not have hemiacetal linkage. The acid hydrolysis of A leads to a laevorotatory solution. A is sucrose which is dextrorotatory, on acid hydrolysis gives mixture of $\alpha$-D-glucopyranose and $\beta$-D-fructofuranose, the mixture is laevorotatory.