PSPO 1/PSM 1 Type of Question - Sprint Planning Meeting Timebox - Trying to Resolve Insconsitencies

I have passed the PSM 1 Exam and I am currently studying for the PSPO 1 Exam.  I have the following question that I am asking from the point of view of what the correct answer would be based on Scrum.Org’s current viewpoint. I am getting inconsistent answers from different sources on this question and I am trying to resolve these inconsistencies:

Question:      The latest version of the Scrum Guide does not appear to divide the Sprint Planning meeting into 2 separate meetings that are both time-boxed, as it did in the past.  It all appears to be one meeting with 1 time-box.  Hence, if we have a 2 week Sprint, with a 4 hour time-box for the meeting, and we spend 1 hour on answering the “what” question, we will have 3 hours remaining to answer the “how” question.  This is unlike how it would have been with a previous version of the Sprint Guide (I believe the 2009 Version) where you would have 2 separate 2 hour time-boxes, one for Part 1 and another for Part 2.  In this case, for a 2 week Sprint, if you spend 1 hour answering the ‘what’ question, you would have only 2 hours to answer the ‘how’ question.  Please confirm that the current way of handling this situation is with only 1 time-box, based on my above explanation, having 3 hours available to answer the “how” question, after you used 1 hour to answer the ‘what” question in a 2 week Sprint.