Who proposed that long neck of giraffes evolved due to foraging of leaves on tall trees?

Lamarck

The correct answer is Option (1)-Lamarck

Branching descent and natural selection are the two key concepts of Darwinian Theory of Evolution. Even before Darwin, a French naturalist Lamarck had said that evolution of life forms had occurred but driven by use and disuse of organs. He gave the examples of Giraffes who in an attempt to forage leaves on tall trees had to adapt by elongation of their necks. As they passed on this acquired character of elongated neck to succeeding generations, Giraffes, slowly, over the years, came to acquire long necks. Nobody believes this conjecture any more.