请教两道gmat语法题

请教两道gmat语法题
researchers have announced that the magnetic fields emitted by one manufacturer's security surveillance system, of which type there are 200,000 worldwide, can interfere with pacemakers and that this interaction can bring on missed or irregular heartbeats, nausea, breathlessness, dizziness, and even fainting.
a.of which type there are 200,000 worldwide, can interfere with pacemakers and that
b. of which, worldwide, there are 200,000 of that type, and which can interfere with pacemakers, and
c. of which type there are 200,000 worldwide, they can interfere with pacemakers and
d, 200,000 of which type exist worldwide, interfering with pacemakers, and
e. 200,000 of that type existing worldwide and can interfere with pacemakers, and
answer: d
本人认为如果选 D,则无谓语.觉得应该选A.
most of the pruported health benefits of tea comes from antioxidants---- compounds also found in beta carotene, vitamin E, adn vitamin C that inhibit the formation of plaque along the body's blood vessels.
a. comes from antioxidants---- compounds also found in beta carotene, vitamin E, adn vitamin C that
b. comes form antioxidants---compounds that are also found in beta carotene, vitamin E, and vitamin C, and they
c.come from antioxidants---compounds also found in beta carotene, vitamin E, and bitamin C and
d. come from antioxidants---coumpounds that are also found in beta carotene, bitamin E, and bitamin C and that
e. come from antioxidants---compounds also found in beta carotene, vitamin E, and vitamin C, and they
本人选了C,不明白为什么答案是D.
希望各位大牛多多指教! 谢谢!