Based on the balance on the account and the amount purchased, the balance on the Equipment office account was A. Debit $5,090.
The opening balance for the Equipment office account was $4,400 on May 1.
The store then purchased a calculator for the office on May 1 for $690. This will increase the Equipment office account by the same amount.
The balance would therefore be:
= 4,400 + 690
= $5,090
This balance would be a debit as this is an asset.
In conclusion, option A is correct.
Find out more about debiting assets at https://brainly.com/question/24164976.