The answer is (b), 1.25 mSv/h.
125 millirem (mrem) = 1250 microsieverts (μSv) = 1.25 millisieverts (mSv). Knowing these conversions is very important when having to communicate with an international audience. In fact, many scientific journals and reports are written in SI units and many radiation measuring devices show results in SI units. It is not uncommon for emergency responders to carry business card size conversion tables in their pockets.