Correct statements among $(i)$ to $(iv)$ regarding silicones are:
$(i)$ they are polymers with hydrophobic character
$(ii)$ they are biocompatible
$(iii)$ in general,they have high thermal stability and low dielectric strength
$(iv)$ usually they are resistant to oxidation and used as greases.

• A
  $(i), (ii), (iii)$ and $(iv)$
• B
  $(i), (ii)$ and $(iii)$
• C
  $(i)$ and $(ii)$ only
• D
  $(i), (ii)$ and $(iv)$