\(N H_{3} > P H_{3} > A S H_{3} > S b H_{3}\)
\(N H_{3}\) is the most basic because of its small size, the electron density of electron pair is concentrated over small region. As the size increases, the electron density gets diffused over a large surface area. Hence, the ability to donate the electron pair (basicity) decreases.
The other three statements given are correct.
$(a)$ લુઈસ એસિડિટી ક્રમ : $SiF_4 < SiC_{4} < SiBr_4 < Sil_4$
$(b)$ ગાલન બિંદુ : $NH_3 > SbH_3 > AsH_3 > PH_3$
$(c)$ ઉત્કલન બિંદુ: $NH_3 > SbH_3 > AsH_3 > PH_3$
$(d)$ ડાઈપોલ નો ક્રમ r : $NH_3 > SbH_3 > AsH_3 > PH_3$