Final answer:
A thymectomy of a 25 year old male will result in immunodeficiency due to lack of new T-cells being produced.
Step-by-step explanation:
A thymectomy is a surgical removal of the thymus gland, which is responsible for the maturation of T cells in the immune system. Therefore, removal of the thymus will result in a lack of new T cells being produced, leading to immunodeficiency. B cells, on the other hand, are not directly affected by the removal of the thymus and can still produce antibodies in response to an infection.
In conclusion, the correct answer is a. Immunodeficiency due to lack of new T-cells being produced.