What is the number of species acting as electrophile and nucleophile respectively, from the following list?

$\stackrel{\oplus }{\mathrm{N}}{\mathrm{O}}_2^{} , {\mathrm{AlCl}}_{3 }, {\mathrm{NH}}_3 , {\mathrm{CH}}_3{\mathrm{NH}}_2 , \mathrm{R}\stackrel{⊝}{\mathrm{O}}, \stackrel{⊝}{\mathrm{C}}{\mathrm{H}}_3 ,\stackrel{\oplus }{\mathrm{C}}{\mathrm{H}}_3 , \stackrel{\bullet }{\mathrm{C}}{\mathrm{H}}_3$

 

(a) ${\mathrm{CH}}_2={\mathrm{CH}}_2$                 

(b) ${\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{N}$

(c) 

(d) 

Which of the above can behave both as an electrophile as well as a nucleophile?

I 

II 

The effect of benzene ring in compound (I) and (II), respectively, will be: