d
(d) Power consumed means heat produced.
For constant potential difference \({P_{{\rm{consumed}}}} = {\rm{Heat}} \propto \frac{1}{{{R_{eq}}}}\)
\(\therefore \frac{{{H_1}}}{{{H_2}}} = \frac{{{R_2}}}{{{R_1}}} = \frac{{R/2}}{{2R}} = \frac{1}{4}\)
(Since \({R_2} = \frac{{R.R}}{{R + R}} = \frac{R}{2}\)and \({R_1} = R + R = 2R)\)