Chemistry · Classification of Elements and Periodicity in Properties

Consider the following statements regarding early attempts at classification of elements: (A) Johann Dobereiner noticed similarities in physical and chemical properties of several groups of three elements called triads. (B) John Alexander Newlands proposed the Law of Octaves in 1865. (C) A.E.B. de Chancourtois made a cylindrical table of elements in 1862. (D) Lothar Meyer published his periodic table before Dmitri Mendeleev. Which of the above statements are correct?

1. A
   All (A), (B), (C) and (D)
2. B
   (A) and (C) only
3. C
   (B) and (D) only
4. D
   (A), (B) and (C) only