The chain length of silicones can be controlled by adding:
1.  \(\mathrm{CH_3SiCl_3}\)
2.  \(\mathrm{SiCl_4}\)
3.  \(\mathrm{(CH_3)_2SiCl_2}\)
4.  \(\mathrm{(CH_3)_3SiCl}\)

The compound among the following that used in cosmetic surgery is:

1. Silica

2. Silicates

3. Silicones

4. Zeolites