What was the basis for Mendeleev's classification of elements in his periodic table?

"The properties of elements are periodic functions of their atomic weights." This periodic law was given by

Write the drawbacks in Mendeleev's periodic table that led to its modification.

Name the scientists who contributed to the development of the periodic table and state their respective laws or contributions.

The most important active step in the development of the periodic table was taken by

Given below are two statements :
Statement $(I):$ According to the Law of Octaves,the elements were arranged in the increasing order of their atomic number.
Statement $(II) :$ Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.
In the light of the above statements,choose the correct answer from the options given below :