Final answer:
The following sentences employ the KISS formula are A. Open the file and select "New." and C. Please respond as soon as possible.
Step-by-step explanation:
Out of the given sentences, both A and C employ the KISS formula. A. Open the file and select "New." This sentence is concise, using simple and direct language. It follows the principle of keeping the sentence short and to the point. C. Please respond as soon as possible. This sentence uses clear and straightforward language, avoiding unnecessary complexity or confusion.
On the other hand, sentence B does not follow the KISS formula. It contains additional phrases and qualifiers that are not essential to the message being conveyed. Sentence D is a subjective statement and does not pertain to the use of the KISS formula. Therefore the correct answer is A. Open the file and select "New." and C. Please respond as soon as possible.