Which of the following is correct order of decreasing rate of elimination of with various bases
(a)$RO^-$ > $OH^-$ > $CN^-$ > $COO^-$ >$NO_3^-$
(b)$NO_3^-$ > $COO^-$ > $CN^-$ > $OH^-$ > $RO^-$
(C)$CN^-$ > $OR^-$ > $NO_3^-$ > $COO^-$ >$OH^-$
(d)$OH^-$ > $COO^-$ >$NO_3^-$ > $OR^-$ > $CN^-$
