We have measured the deuteron A(Q2) structure function in the momentum transfer region between 1 and 18 fm−2. The accuracy of the data ranges from 2 to 6%. These measurements allow a sensitive test of theoretical predictions. We find that meson-exchange currents and relativistic corrections significantly improve the agreement between experiment and theory. We investigate the sensitivity of A(Q2) to the nucleon-nucleon interaction and to the neutron electric form factor GEn(Q2). Our analysis shows that GEn(Q2) can be extracted from these data with a significantly improved accuracy. The model dependence of this analysis is discussed.