An antibody molecule is represented as ${\mathrm{H}}_2{\mathrm{L}}_2$ . This implies that

Read the following statements
I) ${\mathrm{T}}_{\mathrm{C}}$ lymphocytes are involved only in cell mediated immunity.
II) Thymus gland of mammals is a secondary lymphoid organ.
III) The part of antibody that recognises and binds to an antigen is called epitope.
IV) Interleukins are primarily involved in differentiation of the cells of immune system.

Among the above, the incorrect statements are

Study the following:
Statement $\mathrm{I}$: ${\mathrm{T}}_{\mathrm{H}}$ cells are involved in humoral and cell mediated immunity.
Statement $\mathrm{II}$ : Natural killer cells are a type of lymphocytes.

The correct option among the following is

Match the following:

The correct match is