Concept:The use of the infinitive form "to + base verb" is required after certain expressions, not the past participle "
improved".
Explanation:The error is in part (c): "
to improved glucose control".
The phrase "
importance of walking to improved" incorrectly uses the past participle "
improved" after "
to".
In English grammar, when "
to" functions as part of an infinitive (to + verb), the base form (V1) of the verb must follow, not the past tense (V2) or past participle (V3).
Thus, "
to improved" should be "
to improve".
The correct phrase is "
importance of walking to improve glucose control".
The other parts (a) and (b) are grammatically correct.
Therefore, the error lies in part (c).
Answer:Option (c)