Which of the following is NOT true?

Option 2 is NOT true.

One of the conclusions of Maxwell's equations was not the existence of gravitational waves. Maxwell's equations describe the behavior of electric and magnetic fields and their interactions, but they do not directly address gravitational waves. Gravitational waves are predicted by Einstein's theory of general relativity, which is a separate and distinct theory from Maxwell's electromagnetism.

 The existence of gravitational waves was predicted by Einstein in 1916 and finally confirmed in 2016; that's 100 years later !