Observe the following statements :
$a$. The thermal stability of hydrides of group $16$ elements follows the order :
$H_2O > H_2S > H_2Se > H_2Te$
$b$. Acidic nature of hydrides of group $16$ elements follows the order :
$H_2O < H_2S < H_2Se < H_2Te$
$c$. The reducing nature of $H_2S$,$H_2Se$ and $H_2Te$ follows the order :
$H_2S < H_2Se < H_2Te$
The correct statements are:

• A
  $a, b, c$
• B
  $a, b$
• C
  $b, c$
• D
  $a, c$