Final answer:
Diane Doolittle can find the connected apps in a client's QuickBooks Online company by navigating to the 'gear icon > account and settings > apps' within the QuickBooks Online interface. Therefore , the correct answer options is d)
Step-by-step explanation:
To quickly check which apps are connected to a client's QuickBooks Online company, Diane Doolittle can go to: gear icon > account and settings > apps. Once in the Account and Settings menu, selecting the Apps section will display a list of all the apps that are currently connected to the client’s QuickBooks Online account.
This section is designed specifically for managing app connections and should provide Diane with the information she needs in a convenient and efficient manner.