Explanation:

Box 1: true
The oauth2AllowImplicitFlow attribute Specifies whether this web app can request OAuth2.0 implicit flow access tokens. The default is false. This flag is used for browser-based apps, like JavaScript single-page apps.
In implicit flow, the app receives tokens directly from the Azure Active Directory (Azure AD) authorize endpoint, without any server-to-server exchange. All authentication logic and session handling is done entirely in the JavaScript client with either a page redirect or a pop-up box.
Box 2: requiredResourceAccess
With dynamic consent, requiredResourceAccess drives the admin consent experience and the user consent experience for users who are using static consent. However, this parameter doesn't drive the user consent experience for the general case.
resourceAppId is the unique identifier for the resource that the app requires access to. This value should be equal to the appId declared on the target resource app.
resourceAccess is an array that lists the OAuth2.0 permission scopes and app roles that the app requires from the specified resource. Contains the id and type values of the specified resources.
Example:
"requiredResourceAccess": [
{
"resourceAppId": "00000002-0000-0000-c000-000000000000",
"resourceAccess": [
{
"id": "311a71cc-e848-46a1-bdf8-97ff7156d8e6",
"type": "Scope"
}
]
}
],
Box 3: AzureADMyOrg
The signInAudience attribute specifies what Microsoft accounts are supported for the current application.
Supported values are:
AzureADMyOrg - Users with a Microsoft work or school account in my organization's Azure AD tenant (for example, single tenant) AzureADMultipleOrgs - Users with a Microsoft work or school account in any organization's Azure AD tenant (for example, multi-tenant) AzureADandPersonalMicrosoftAccount - Users with a personal Microsoft account, or a work or school account in any organization's Azure AD tenant Reference:
https://docs.microsoft.com/en-us/azure/active-directory/develop/reference-app-manifest
https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-implicit-grant-flow

If you want to read the files in parallel, you cannot use forEach. Each of the async callback function calls does return a promise. You can await the array of promises that you'll get with Promise.all.
Scenario: Capacity issue: During busy periods, employees report long delays between the time they upload the receipt and when it appears in the web application.

Reference:
https://stackoverflow.com/questions/37576685/using-async-await-with-a-foreach-loop

Explanation:

Box 1: Yes
The ItemDescription field in not searchable.
Box 2: No
The ItemDescription field in not searchable, but we would need to recreate the index.
Box 3: Yes
An indexer in Azure Search is a crawler that extracts searchable data and metadata from an external Azure data source and populates an index based on field-to-field mappings between the index and your data source.
This approach is sometimes referred to as a 'pull model' because the service pulls data in without you having to write any code that adds data to an index.
Box 4: No
References:
https://docs.microsoft.com/en-us/azure/search/search-what-is-an-index
https://docs.microsoft.com/en-us/azure/search/search-indexer-overview