One line of the pair of lines $x^2+x y-2 y^2=0$ is perpendicular to one line of the pair of lines $3 y^2-5 x y-2 x^2=0$. If the combined equation of the two lines other than those two perpendicular lines is $a x^2+2 h x y+b y^2=0$, then $a+2 h+b=$

• A

  -1
• B

  1
• Correct answer
  C

  0
• D

  -5

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