Collin Printing began operations on January 1. On January 7, Collin purchased supplies on account for $1,000. At the end of January, Collin had $600 of supplies on hand. The proper journal entry for the January 7 transaction would: include a debit to Supplies for $600. include a credit to Supplies for $400. None of these. include a debit to Supplies for $1,000. include a debit to Supplies Expense for $400