  We present measurements of the B -> eta' K branching fractions;for B+ -> eta'
K+ we measure also the time-integrated charge asymmetry Ach, and for B0 -> eta'
K0S the time dependent CP-violation parameters S and C. The data sample
corresponds to 232 million B Bbar pairs produced by e+ e- annihilation at the
Upsilon(4S). The results are BF(B+ -> eta' K+) = (68.9 +- 2.0 +- 3.2) * 10^-6,
BF(B0 -> eta' K0) = (67.4 +- 3.3 +- 3.2) * 10^-6, Ach = 0.033 +- 0.028 +-
0.005, S=0.30 +- 0.14 +- 0.02, C=-0.21 +- 0.10 +- 0.02, where the first error
is statistical and the second systematic.
