Surveys have shown that in up to 40 percent of elderly people living independently in affluent countries, the consumption of one or more essential nutrients is insufficient or they have deficient levels of these nutrients in their blood.

(A) in up to 40 percent of elderly people living independently in affluent countries, the consumption of one or more essential nutrients is insufficient or they have
(B) in up to 40 percent of elderly people who live independently in affluent countries, they consume one or more essential nutrients insufficiently or have
(C) in up to 40 percent of elderly people who live independently in affluent countries, one or more essential nutrients are consumed insufficiently or having
(D) up to 40 percent of elderly people living independently in affluent countries who consume insufficient amounts of one or more essential nutrients or who have
(E) up to 40 percent of elderly people who live independently in affluent countries consume insufficient amounts of one or more essential nutrients or have

[spoiler]OA: E[/spoiler]

I could not trace "they" in B. I think that "they" refer to people.

Question: What is the actual mistake in B?

Thanks.