I'm confused with how to name accounts.

I answered as "Merchandise Inventory" for a name of the accounts on March 3, because the company purchased merchandise inventory. The answer is "Purchases".

And also, I answered as "Merchandise Inventory" for freight bill on March 4. The answer is "Freight In".

How do I distinguish them?

Journalize the following transactions that occurred in March 2018 for Duble Company. Assume Duble uses the periodic inventory system. No explanations are needed. Identify each accounts payable and accounts receivable with the vendor or customer name. Duble estimates sales returns at the end of each month. (Record debits first, then credits. Exclude explanations from journal entries. Assume the company records sales at the net amount.) i (Click the icon to view the transactions.) Mar. 3: Purchased merchandise inventory on account from Sherry Wholesalers, $3,500. Terms 2/15, n/EOM, FOB shipping point. Date Accounts Debit Credit Mar. 3 Purchases 3,500 3,500 You answered: Merchandise Inventory Mar. 4: Paid freight bill of $75 on March 3 purchase. Date Accounts Debit Credit Mar. 4 Freight In 75 Cash 75 Mar. 4: Purchase merchandise inventory for cash of $2,000. Date Accounts Debit Credit Mar. 4 Purchases 2,000 Cash 2,000 Mar. 6: Returned $1,000 of inventory from March 3 purchase. Date Accounts Debit Credit Mar. 6 Accounts Payable-Sherry Wholesalers 1,000 Purchase Returns and Allowances 1,000