GWD30-20

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.

1. of which type there are 200,000 worldwide, can interfere with
        pacemakers and that
2. of which, worldwide, there are 200,000 of that type, and which
        can interfere with pacemakers, and
3. of which type there are 200,000 worldwide, they can interfere
        with pacemakers and
4. 200,000 of which type exist worldwide, interfering with
        pacemakers, and
5. 200,000 of that type existing worldwide and can interfere with
        pacemakers, and

我也认为应该是Ａ

我觉得A后面and 跟that不合适哦.

因为是强调this interaction,所以应该意义还是包含在之前的that从句里的.

D的确没有谓语,我也歇菜了orz

我乱选了C...

d不见得有错