Which of the following contains the highest concentration of antibodies?

Which of the following is the correct representation of an antibody molecule?

Which of the following is a characteristic of antibodies?

Given below are two statements:
Statement $I$: Bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced.
Statement $II$: Both bone marrow and thymus provide micro-environments for the development and maturation of $T$-lymphocytes.
In the light of the above statements,choose the most appropriate answer from the options given below:

Innate immunity is defined as.........

The antibodies are: