The type or namespace name ‘QueryOption’ could not be found

Starting with Microsoft Graph .NET SDK 5.0, the QueryOption class is no longer used. Instead, query options are set using the requestConfiguration modifier.

Let’s take a simple example:

var groups = await graphServiceClient
    .Groups
    .GetAsync(requestConfiguration =>
    {
        requestConfiguration.QueryParameters.Select = new string[] { "id", "createdDateTime","displayName"};
        requestConfiguration.QueryParameters.Expand = new string[] { "members" };
        requestConfiguration.QueryParameters.Filter = "startswith(displayName%2C+'J')";
    });
Code language: C# (cs)

If you must use QueryOptions, your only alternative is to downgrade the Microsoft Graph package to a 4.x version.