prep115 请教

Many population studies have linked a high-salt diet to high rates of hypertension and shown that in societies where they consume little salt, their blood pressure typically does not rise with age.

(A) shown that in societies where they consume little salt, their

(B) shown that in societies that have consumed little salt, their

(C) shown that in societies where little salt is consumed,

(D) they showed that in societies where little salt is consumed,

(E) they showed that in societies where they consume little salt, their

answer：c

这是什么和什么平行啊 shown和linked平行么

那是短语和从句平行？