At first glance, this question appears to be a mappable parallel question. However, to get to the answer for this question, you do not proceed in the same manner you would through a mappable parallel question as this is a specific type of one of those questions called an "identify the flaw" question.
To proceed, mapping is generally helpful, and with this question it will help you get your mind around what the stimulus is saying. The stimulus says Some tenured professors are not full time professors. It then says that all linguistics professors are tenured, therefore some are not full time. Obviously, there's a huuuuge flaw there! Before you go onto the answer choices, identify the flaw and it may even be helpful to articulate the flaw with a few words beside the stimulus. When I did this practice exam, I remember thinking to myself, "What if all the linguistics professors are tenured and full time and all history professors are tenured but not full time, then it would be true that some tenured are not tenured and full time. Now our task is to find which answer choice exhibits the same flaw. The flaw is basically trying to say, that what is true about the whole is true about the parts. A very bad bad flaw. Let's go through the answer choices now.
A. If it's a modern office towers then it's climate controlled. Not all office buildings are climate controlled. Therefore, not all office buildings are modern towers.
----this is a true statement, and therefore not the correct answer
B. If municipal hospital then it's massive. If municipal hosp, then not necessarily forbidding. Therefore massive buildings need not be massive.
----again, this is a true statement, and thefore not the correct choice.
C. Some buildings designed by fam architects are not well proportioned (read: if it's a building designed by a fam. architect it's not necessarily well proportioned). If gov't building, then designed by a famous architect. Therefore, some gov't bldgs are not well proportioned. This exhibits the same flaw. Say all gov't bldgs are designed by famous architects and they all are well proportioned, but some houses are also designed by famous architects and a bunch of those houses or all of those houses are poorly proportioned, then some buildings designed by famous architects might not be well proportioned but all gov't bldgs are still well proportioned. Again the flaw is, what is true for the whole, is not necessarily true for each of its parts.
If you need help figuring out why D and E are wrong, let me know. However, I think you should be able to map them and figure out why the do not exhibit the flaw in question. The credited response is C.