So, the correct order is order is $\mathrm{F}>\mathrm{Ce}>\mathrm{Br}$
$F C H_{2} C O O H>C l C H_{2} C O O H>B r C H_{2} C O O H>C H_{3} C O O H$
$(A)\,{{C}_{8}}{{H}_{10}}\xrightarrow{KMn{{O}_{4}}}(B){{C}_{8}}{{H}_{6}}{{O}_{4}}\xrightarrow[Fe]{B{{r}_{2}}}{{C}_{8}}{{H}_{5}}Br{{O}_{4}}(C)$ (માત્ર એક જ નીપજ )

