Section: Engineering Mathematics | Marks: 1
Which one of the following partial differential equations CAN NOT be reduced to two ordinary differential equations by the method of separation of variables?

- A. డ௨ డ௧− డమ௨ డ௫మ = 0
- B. డమ௨ డ௧మ− డమ௨ డ௫మ= 0
- C. డమ௨ డ௧మ+ డమ௨ డ௧డ௫+ డ௨ డ௫= 0
- D. డమ௨ డ௧మ+ డమ௨ డ௧డ௫+ డమ௨ డ௫మ= 0