So here we have an example problem that asks, which of the following statements about the thymus is true? And we've got these 4 potential answer options down below. Now, option a says, it is located in the inferior thorax, which is like the lower chest. However, recall from our previous lesson video that this is actually not true. The thymus is located in the upper chest in a region called the mediastinum behind the sternum, between the lungs, and slightly above the heart. And so we can eliminate answer option a since it's not true.
Now option b says, like other lymphoid organs, it contains lymphoid follicles and B cells. However, recall from our last lesson video that the thymus is unique because it actually does not contain lymphoid follicles or lymphoid nodules, which have large populations of B cells. So the thymus does not really have these lymphoid follicles or large populations of B cells. The thymus is extremely specific to the development of T cells. And so, for that reason, we can eliminate answer option b.
Now option c says, it is structurally unique compared to other lymphoid organs due to its lack of lymphoid follicles. And so recall from our last lesson video that this is actually true. The thymus does lack lymphoid follicles, and that is something that helps make it unique compared to other lymphoid organs, which usually do have lymphoid follicles. So option c is going to be the correct answer to this example problem, so we can indicate c is correct.
Now, option d says, after puberty, it stops growing and remains the same throughout life. However, recall that the thymus reaches its maximum size right around puberty. And after puberty, it doesn't just stop growing. It actually atrophies, meaning that it decreases in size and decreases in activity. And so it doesn't remain the same size. It actually decreases in size after puberty. So that's why we can eliminate answer option d.
So again, c here is the correct answer. That concludes this example problem, and I'll see you all in our next video.