What is the period of the cell cycle during which activities such as cell growth and protein synthesis occur without visible signs of cell division

Interphase is the longest period of the cell cycle. During interphase, all of the information in the nucleus is copied, preparing the cell for division. It is during this phase of the cycle that proteins are synthesized and DNA is replicated.

Its interphase i think:

The meaning of Interphase is : the period of the cell cycle during which the nucleus is not undergoingdivision, typically occurring between mitotic or meiotic divisions.