When did Dmitri Mendeleev invent the periodic table, ordering the symbols of the chemical elements according to their atomic weights?

Correct option is B

The correct answer is (b) 1869.
 Dmitri Mendeleev, a Russian chemist, invented the periodic table in 1869.
 He arranged the 63 known elements based on their atomic weights and properties.
 Mendeleev's periodic table left gaps for elements yet to be discovered, predicting their properties with remarkable accuracy.