What is the main reason why wegener's continental drift hypothesis was rejected by his scientific community?

His theory of "continental drift," presented for the first time in January of that year, started a scientific revolution in geology that deeply affected the way we understand how Earth systems work. 

One century ago, in January 1912, Alfred Wegener presented for the first time his theory of "continental drift" at a meeting held in Frankfurt, in Germany (*). Wegener had collected geological and paleontological data that gave weight to an old observation: that the margin of continents on the opposite sides of the Atlantic Ocean seemed to correspond; as in a gigantic puzzle. Accordingly, Wegener proposed that the present continents were once joined together but had slowly drifted away from each other of hundred of millions of years.

The answer is number 4.