Which of the following is the correct order of decreasing S_N2 reactivity?

In the following sequence of reactions,
CH₃CH₂OH $$\buildrel {P + {I_2}} \over \longrightarrow $$ A $$\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{ether}^{Mg}} $$ B $$\buildrel {HCHO} \over \longrightarrow $$ C $$\buildrel {{H_2}O} \over \longrightarrow $$ D
the compound ‘D’ is

Which one of the following is the strongest base in aqueous solution?

In the chemical reaction,
CH₃CH₂NH₂ + CHCl₃ + 3KOH $$\to$$ (A) + (B) + 3H₂O, the compound (A) and (B) are respectively