Answer:
d. Do at least 30 minutes of exercise, like brisk walking, most days of the week
Explanation:
PLAIN or Plain Language Association International is meant to support the use of simple language in government documents.
Government documents based on PLAIN will be easy to read and understand by the citizens as it carries short and ordinary sentences that are more effective.
The most effective revision of this document from the given options is "d" as it represents simple language which is easy to understand in comparison to other given sentences.
Hence, the correct option is "d".