While Searching the Relevant Computer Files,pursuant to a Search Warrant

While searching the relevant computer files,pursuant to a search warrant for the crime of distribution of child pornography,officers find reference to a "customer ledger." After this information is discovered,an officer observes a notebook lying on the kitchen counter with the words "customer ledger" written on the front cover.The officers may:

A) seize and open the notebook immediately without obtaining a warrant.
B) seize the notebook immediately, but need a warrant before opening the notebook.
C) not seize or search the notebook without obtaining a new warrant.
D) seize the notebook, but cannot open it unless instructed to do so by a judge.