Of the following, the best example of an opening for an information response is $\_\_\_\_\_\_\_\_.$

Question $2$ options:

$1)$

"I am writing in response to your memo of August $21"$

$2)$

"Thank you for your memo of August $21"$

$3)$

"I received your request for information on health plan options last week"

$4)$

"Attached is a brochure that details the health plan options you requested"