Which of the following blood components provide the major defense for
our bodies against invading bacteria and viruses?

B lymphocytes are involve in helping the T-cells to fight against the bectaria, viruses, or fungi etc.

Explanation:

lymphocyte is a form of small leucocyte.

White blood cells which are known as leucocytes are grouped into two main types: granulocyte and Agranulocyte. lymphocytes are catogorized under Agranulocytes. lymphocytes having a life span of month or even years depend on the body need of a cell.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.