Proteins can be classified into two types on the basis of their molecular shape i.e., fibrous proteins and globular proteins. Examples of globular proteins are:

The correct option is C Insulin
On the basis of molecular shape, proteins are classified into two types$-$fibrous proteins and globular proteins.

$\text{Fibrous proteins}:$

The proteins in which the polypeptide chains lie parallel (side by side) and are held together by hydrogen and disulphide bonds to form fibre-like structure are called fibrous proteins.
Example: myosin (in muscles), keratin (in hair, wool, nails, skin), etc.

$\text{Globular proteins}:$

The proteins which are folded to form spherical structure and have intramolecular hydrogen bonding are called globular proteins.

Example: Haemoglobin (in blood), albumin (in eggs), insulin (in pancreas), etc.

Hence, from the above description it is concluded that option $\left(A\right)$ and option $\left(C\right)$ are correct.