What is the condition that one root of the equation $a x^2+b x+c=0, a \neq 0$ should be double the other?

• A

  $2 a^2=9 b c$
• Correct answer
  B

  $2 b^2=9 a c$
• C

  $2 c^2=9 a b$
• D

  None of the above

Hence, the correct answer is option: 'B'.