Consider the following statements. Which of the following statements are correct?
$(i)$ Froth floatation technique is used to concentrate sulphide ore.
$(ii)$ Froth floatation technique is based upon differential wettability of ore and impurity in water.
$(iii)$ Red Bauxite is concentrated by Bayer’s process.
$(iv)$ Carbon is used as reducing agent during extraction of zinc from zinc blende.

• A
  $(i)$ and $(ii)$
• B
  $(ii)$ and $(iii)$
• C
  $(i), (iii)$ and $(iv)$
• D
  All are correct