Which query is not Buffered Internally with Split Query when MARS is disabled?

Question

I was reading the efficient querying microsoft article and there is a part which is unclear to me:

When split query is used, the resultsets of all but the last query are buffered - unless MARS (Multiple Active Result Sets) is enabled on SQL server.

To illustrate my question, let assume I have a code that creates 3 query:

var questionsStream = stackoverflowContext.Set<Question>()
    .Include(q => q.Statistics)
    .Include(q => q.Answers)
    .AsSplitQuery();

foreach (var question in questionsStream)
//...

Which table result is streamed?

• Question table,
• Answer table,
• random/depends on (what?)

If it is the last Include() I should order my Includes to have the possibly longest one at the end of the chain (to spare memory), right?

I searched SO for "internal buffering", "split query", "ef streaming", "ef MARS" and similar terms before asking the question. I found out what happens if MARS is enabled by this SO post, but no answer to what happens when it is disabled.