Question

A man who has been exposed to the flu virus is tested by his physician. The physician notes that the virus is present but no measurable level of antibodies corresponding to the virus are detected in his body.

What might this mean?

A He was probably exposed sometime within the past two weeks, but we don't have enough information to say more.

B He was probably exposed a few days ago and clonal selection has yet to produce plasma cells.

C He was probably exposed more than several months ago, antibody production has ceased, and antibodies are no longer detectable.

Answer 1

The absence of measurable levels of antibodies suggests that the person was exposed to the flu virus several months ago and antibody production has ceased.

Step-by-step explanation:

The absence of measurable levels of antibodies in the body of a person who has been exposed to the flu virus suggests that the person was probably exposed more than several months ago. Antibody production ceases after a certain period, and the antibodies may no longer be detectable in the body. Therefore, option C, "He was probably exposed more than several months ago, antibody production has ceased, and antibodies are no longer detectable," is the correct answer.