$\mathrm{A}=\mathrm{RCOOH},\mathrm{B}={\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OH},\mathrm{C}={\mathrm{H}}_2\mathrm{O},\mathrm{D}=\mathrm{R}-\mathrm{OH},\mathrm{E}=\mathrm{CH}\equiv \mathrm{CH},\mathrm{F}={\mathrm{NH}}_3$ Correct acidic strength

Greater the stability of anion produced due to deprotonation, greater will be the strength of a species.

A) RCOO^- has equivalent resonance structures which are indistinguishable. It is the most stable anion.

B) C₆H₅O^—  is resonance stabilised, in C₆H₅O^- negative charge is delocalized on carbon atom also.

C) HO^- and RO^- are not resonance stabilized but they have negative charge on electronegative oxygen atom. They are more stable than $\mathrm{CH}\equiv \overline{\mathrm{C}}\mathrm{and}{\mathrm{NH}}_2^{-}$

Stability of HO^- > RO^-  because in RO^- charge accumulation occurs due to +I effect of –R. 

D) Stability of $\mathrm{CH}\equiv \overline{\mathrm{C}}>{\mathrm{NH}}_2^{-}$ because electronegativity of sp-carbon is greater than sp³ – nitrogen. Thus stability of 

 ${\mathrm{RCOO}}^{-}>{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{O}}^{-}>{\mathrm{HO}}^{-}>{\mathrm{RO}}^{-}>\mathrm{CH}\equiv \overline{\mathrm{C}}>{\mathrm{NH}}_2^{-}$

Acidic strength of A > B > C > D > E > F.