You need to query Dataverse metadata for the email address attribute in the Accounts table. 
Please select the correct REST API statement for your org API endpoint https://yourorg.api.crm.dynamics.com/api/data/v9.2/.

Answer options:

A.GET /EntityDefinitions(`account`)/Attributes(`emailaddress1`)
B.POST /EntityDefinitions(SchemaName=`account`)/Attributes(LogicalName=`emailaddress1`)
C.GET /EntityDefinitions(LogicalName=`account`)/Attributes(LogicalName=`emailaddress1`)
D.GET /EntityDefinitions(SchemaName=`account`)/Attributes(LogicalName=`emailaddress1`)
E.POST /EntityDefinitions(LogicalName=`account`)/Attributes(LogicalName=`emailaddress1`)
F.POST /EntityDefinitions(`account`)/Attributes(`emailaddress1`)

Correct Answer: C 
Microsoft Dataverse provides the capability of querying the metadata during the run-time by using REST API. 
Here is the typical statement for querying the Dataverse’s tables, like account, and select name and email: 
GET {endpoint}/accounts?$select=name,emailaddress1&$top=3 
There are two ways to query the metadata by Name or MetadataID. To query the Dataverse metadata, you need to add the EntityDefinitions to your path. 
To query the Dataverse metadata by name, you need to use the “LogicalName” alternate key for the entities and attributes. Here is the statement with the EntityDefinitions: 
GET /EntityDefinitions(LogicalName=`account`)/Attributes(LogicalName=`emailaddress1`) 
Here is a snapshot of a JSON response. It contains complete metadata information about the “emailaddress1’ attribute, including the MetadataID (Number 1). You can retrieve an entity MetadataID by dropping the /Attributes… part from the above statement and query only on the entity. 

And here is a query with the MetadataID for the same entity and attribute: 
GET /EntityDefinitions(70816501-edb9-4740-a16c-6a5efbc05d84)/Attributes(b254ab69-de5a-4edb-8059-bdeb6863c544) 
All other options are incorrect. 
For more information about querying the Dataverse metadata by the Web API, please visit the below URLs: 

https://docs.microsoft.com/en-us/powerapps/developer/data-platform/webapi/retrieve-metadata-name-metadataid#retrieve-metadata-items-by-name
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/webapi/retrieve-metadata-name-metadataid#retrieve-metadata-items-by-metadataid