When did the worst environmental nuclear power plant accident and the $MIC$ gas tragedy occur,respectively?

• A
  $1990$ in Russia and $1986$ in Bhopal
• B
  $1988$ in Ukraine and $1984$ in $USA$
• C
  $1984$ in Bhopal and $1990$ in Russia
• D
  $1986$ in Ukraine and $1984$ in Bhopal