A forensic investigator suspects that spyware has been installed to a Mac OS X computer...

Comprehensive and Detailed Explanation From Exact Extract:

The/Library/Receiptsfolder on Mac OS X contains receipts that track software installation and updates, including system and application updates. This folder helps forensic investigators determine which updates were installed and when, useful for detecting suspicious or unauthorized software installations like spyware.

/var/spool/cupsis related to printer spooling.

/var/log/daily.outcontains daily system log summaries but not detailed update records.

/var/vmcontains virtual memory files.

NIST and Apple forensics documentation indicate that/Library/Receiptsis a key location for examining software installation history.