Answer:
Hey there!
This is an indirect object because it is the pronoun, noun, or noun phrase that receives the direct object of a verb.
Let me know if this helps :)
C. a memory aid
A mnemonic is a memory aid, usually a phrase or visual, that helps you remember a fact.
That the Roman Empire was a gargantuan power and reached to almost all of the known world at the time of greatest land holdings
Diary Keeping it is usually a written record of personal experiences and observations. It is also a daily record of events or measurable phenomena, usually kept to track patterns over time. A book or computer file can be used for keeping such a record.
Record Keeping it is the maintenance of a history of one's activities, as financial dealings, by entering data in ledgers or journals, putting documents in files.