  The large discrepancy recently observed between $B \ra J/\Psi + K (K^*)$ data
and commonly used hadronic form factor models might be due to a breakdown of
the factorization assumption. By showing that the $B \ra \eta_c + K (K^*)$
rates can be calculated without relying on any form factor model, we propose a
test of the factorization hypothesis. This test is free of possible
uncertainties caused by final state interactions and $W$-exchange graph
contributions. If factorization holds, the measurable ratio $\Gamma(B \ra
\eta_c + K^*)/\Gamma(B \ra \eta_c + K )$ is predicted to be in the range from
0.18 to 0.95 when the CLEO II data on $B \ra J/\Psi + K (K^*)$ are used.
