While Searching the Relevant Computer Files Pursuant to a Search

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 legally _____.

A) seize and open the notebook immediately without obtaining a warrant.
B) seize the notebook immediately, but will 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