# Which of the following order is wrong ?

$(a)\;NH_3 < PH_3 < ASH_3 \;-acidic \\(b)\;Li < Be < B < C -(IE), \\ (c)\;Al_2O_3 > MgO < Na_2O < K_2 O \\ (d)\;Li^{+} < Na^+ < K^+ -Cos^+ -ionic\; value$

Wrong order is $Li < Be < B < C -(IE)$
Hence b is the correct answer.
edited Sep 30