Multi-choice problem: Continue writing the next sentence in this paragraph:

How to synthesise organic compounds
Check if the starting chemical is a mixture.
If your starting chemical is something like crude oil, you'll need to use distillation or fractional distillation to separate it into parts.
See if the starting and target chemicals have any groups in common.

Possible answers: a). Make sure they are all easy to combine. Obtain an active source of this substance.. b). For example, they may contain an amine group or a carboxyl group, etc. If the starting chemical is a mixture, look at which parts can be used.. c). Each chemical has its group's atomic radius and its " base " number of atoms. To discover the atomic radius, tap a surface with a note board or jot the atomic radius.. d). Sometimes they are grouped into what is called a " boundary " area of the 1.5 chemical composition (nacl. ) this area is commonly found in calcium, zinc, and nitrate..
b).