  Six binary-merger progenitors of Supernova 1987A (SN 1987A) with properties
close to those of the blue supergiant Sanduleak -69 202 are exploded by
neutrino heating and evolved until long after shock breakout in three
dimensions (3D), and continued for light-curve calculations in spherical
symmetry. Our results confirm previous findings for single-star progenitors:
(1) 3D neutrino-driven explosions with SN 1987A-like energies synthesize Ni-56
masses consistent with the radioactive light-curve tail; (2) hydrodynamic
models mix hydrogen inward to minimum velocities below 40 km/s compatible with
spectral observations of SN 1987A; and (3) for given explosion energy the
efficiency of outward radioactive Ni-56 mixing depends mainly on high growth
factors of Rayleigh-Taylor instabilities at the (C+O)/He and He/H composition
interfaces and a weak interaction of fast plumes with the reverse shock
occurring below the He/H interface. All binary-merger models possess
presupernova radii matching the photometric radius of Sanduleak -69 202 and a
structure of the outer layers allowing them to reproduce the observed initial
luminosity peak in the first about 7 days. Models that mix about 0.5 Msun of
hydrogen into the He-shell and exhibit strong outward mixing of Ni-56 with
maximum velocities exceeding the 3000 km/s observed for the bulk of ejected
Ni-56 have light-curve shapes in good agreement with the dome of the SN 1987A
light curve. A comparative analysis of the best representatives of our 3D
neutrino-driven explosion models of SN 1987A based on single-star and
binary-merger progenitors reveals that only one binary model fulfills all
observational constraints, except one.
