Which of the following statements about the development of lymphocytes is correct?

• A. T cells are produced in the thymus & B cells are produced in red bone marrow.
• B. T & B cells are both produced in red bone marrow, & they both mature in the thymus.
• C. T & B cells are both produced in red bone marrow, but only T cells mature in the thymus.
• D. T & B cells are both produced in the thymus & also mature in red bone marrow.