TMEP § 1110.08
Filing a request to divide is not a proper response to an Office action and does not relieve an applicant of the duty to respond to any outstanding Office action or to take any other required action.
Any outstanding deadline in effect at the time the application is divided applies not only to the original application, but also to each new application created by the division of the application. 37 C.F.R. §2.87(e). Therefore, if a response to an Office action is due, the response is due in each separate new application created by the division of the application, unless one of the following exceptions applies:
37 C.F.R. §2.87(e)(1)-(2).
If the applicant files a request to divide goods/services that are subject to a refusal from goods/services that are not subject to a refusal, the USPTO puts the goods/services that are not subject to refusal in the new (child) application, and retains the goods/services that are subject to refusal in the original (parent) application. More child applications may later be created from the parent application.
When a request to divide is filed with a response to an Office action, the response should be entered first, and then the request to divide should be referred to the ITU/Divisional Unit. The ITU/Divisional Unit will process the request and then return the application to regular processing. See TMEP §1110.04 regarding the form and processing of requests to divide.