English Grammar — Error Spotting (Collocations: vary / one another) Identify the part that contains a grammatical error. If there is no error, choose 'No error'. Full sentence: All individuals are different so their tastes vary from one another.

Introduction / Context:
This item checks idiomatic collocations with "vary" and the correct completion of the phrase. While "differ from one another" is common, with "vary" the natural phrasing is "vary from person to person" or "vary from one person to another."

Given Data / Assumptions:

• Sentence: "All individuals are different so their tastes vary from one another."
• We select the fragment that makes the sentence non-idiomatic.

Concept / Approach:

The verb "vary" commonly takes complements like "from person to person" or "widely/considerably," whereas "one another" typically follows "differ from one another." Thus, the completion "vary from one another" is not idiomatic.

Step-by-Step Solution:

1) Identify the collocation around "vary from ...".2) Recognize that the complement should be "person to person" or "one person to another."3) Therefore the fragment "one another" is the problematic part.4) A corrected version: "All individuals are different, so their tastes vary from person to person."

Verification / Alternative check:

Substitute "differ" to test: "tastes differ from one another" reads better, confirming that "vary" is mismatched with "one another" in this construction.

Why Other Options Are Wrong:

A: Grammatically fine subject and copula.B: Coordination is acceptable; a comma before "so" is optional stylistically.C: "tastes vary from" is fine until the complement appears.E: Not correct, since D is the problem.

Common Pitfalls:

Overgeneralizing "one another" after any comparative verb leads to awkwardness. Match collocations precisely: "differ from one another" vs "vary from person to person."

Final Answer:

one another.