The correct order of acceptor ability of the phosphorus ligands is
(a)$\mathrm{PMe_3 > PPh_3 > P(OPh)_3 > PF_3}$
(b)$\mathrm{PF_3 > P(OPh)_3 > PPh_3 > PMe_3}$
(c)$\mathrm{PF_3 > PMe_3 > PPh_3 > P(OPh)_3}$
(d)$\mathrm{P(OPh)_3 > PF_3 > PMe_3 > PPh_3}$
Answer
Answer (as printed): B
Explanation
As the electronegativity of X in $\mathrm{PX_3}$ increases, $\pi$-acceptor tendency increases.$\mathrm{PF_3} > \mathrm{P(OPh)_3} > \mathrm{PPh_3} > \mathrm{PMe_3}$