Sentence Correction

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. showing that in societies where little salt is consumed
E. showing that in societies where they consume little salt, their

C

A. shown that in societies where they consume little salt, their
Pronoun "their" - must not refer to societies or studies to have a clear meaning. However, it does so. Hence, incorrect.

B. shown that in societies that have consumed little salt, their
Same error as that in option A.

C. shown that in societies where little salt is consumed
Correct. Uses correct parallel verb form: have linked ...and (have) shown. Also, does not uses any ambiguous pronoun.

D. showing that in societies where little salt is consumed
verb form - "showing" is not parallel with"linked. Hence, incorrect.

E. showing that in societies where they consume little salt, their
Same error as that in option A.