Specify the identifying keys for the responses whose values and
sensitivities are to be written to the output database. Only one response key can be
specified in an adjoint design sensitivity analysis. The valid keys are listed in
Direct Design Sensitivity Analysis and Adjoint Design Sensitivity Analysis.
In a direct design sensitivity analysis, repeat this data line as
often as necessary to define the nodal responses whose values and sensitivities are to
be written to the output database.