Among the following,the correct statement$(s)$ about polymers is(are):
$A$. The polymerization of chloroprene gives natural rubber.
$B$. Teflon is prepared from tetrafluoroethene by heating it with persulphate catalyst at high pressures.
$C$. $PVC$ are thermoplastic polymers.
$D$. Ethene at $350-570 \ K$ temperature and $1000-2000 \ atm$ pressure in the presence of a peroxide initiator yields high density polythene.

• A
  $A, B, C$
• B
  $B, A$
• C
  $B, D$
• D
  $B, C$