On the basis of the isobar model extended by including the t-channel, the cross sections for and single-polarization features of the reaction γp → η′p are calculated for incident-photon energies up to 5 GeV, two poorly studied resonances, S11(1978) and P13(2080), being taken into account in this calculation. In order to reduce the ambiguities in the choice of resonances and their parameters that make it possible to reproduce the experimental differential cross sections, it is proposed to measure the polarization of recoil protons in the reaction being considered.