You are carrying triethylamine，methyl methacrylate and isoprene in your multiple-product tanker. Which of the following statements is true? （）
- AIsoprene may be carried in a cargo tank adjacent to either of the other two cargoes
- BMethyl methacrylate may not be carried in a tank adjacent to a pump room
- CMethyl methacrylate must usually be heated to maintain its stability
- DPortable thermometers are not permitted to be used to take the cargo temperature of triethylamine