According to recent studies comparing the nutritional value of meat from wild animals and meat from domesticated animals, wild animals have less total fat than do livestock fed on grain and more of a kind of fat they think is good for cardiac health.

1. wild animals have less total fat than do livestock fed on grain and more of a kind of fat they think is
2. wild animals have less total fat than livestock fed on grain and more of a kind of fat thought to be
3. wild animals have less total fat than that of livestock fed on grain and have more fat of a kind thought to be
4. total fat of wild animals is less than livestock fed on grain and they have more fat of a kind thought to be
5. total fat is less in wild animals than that of livestock fed on grain and more of their fat is of a kind they think is

此题GWD22说是B，但我觉得B如果作为正确答案，应该补出比较部分的谓语动词，即：wild animals have less total fat than do live stock fed......

大家觉得呢？