The $IUPAC$ nomenclature of $CH_3-C(CH_3)_2-CH=C(CH_3)_2$ is

Caffeic acid is found in coffee beans. What is its $IUPAC$ name?

The $IUPAC$ name of the following compound is:

What is the name of $\text{tert-butyl}$ alcohol according to the carbinol system?

Write $IUPAC$ names of the following structures:
$(A)$ $CHO-CHO$
$(B)$ $A$ benzene ring with two $CHO$ groups at para positions.
$(C)$ $A$ benzene ring with a $Br$ group and a $CHO$ group at meta positions.

Provide the $IUPAC$ name for the given compound.