North has lots of points, just about maximum for a 1-level opening.
With four hearts and four spades we prefer to open the lower of two touching majors. By opening one of a suit we are starting a conversation with our partner and intend to describe the hand further by subsequent bids. All partner knows at the moment is that we have opening points and at least four hearts.
South's hand is a little better than minimum and you have a response to describe this - 1NT showing 6 - 9 points, denies four hearts or four spades. Do not pass on this type of hand - you want to know more about partner's hand. And if partner says "hello" surely you want to say hello back if possible!
Focus on the opening hand now, repeating the opening suit would show length in that suit. Here we want to show points. No trump rebids do this. As partner has already bid NT all you have to do is raise to 3NT to show a maximum hand and confirm that the partnership holds the required 25 plus points needed for game
West is on lead and selects the ♠K, top of a sequence and a suit not bid by north/south so you hope they do not have too many.
Plan the play. You have nine top tricks so you can make your contract as long as you can cash five tricks in clubs. What problems might you have?
Even though North has four spades you only have one stop so spades are the danger suit. By leading spades the opposition have removed your only entry to the long clubs.
It is usually right to hold up when you only have the ace of the suit lead but on this occasion that will not help so you win the spade lead, then play ♣A and ♣Q overtaking the queen with the king, holding your breath that the clubs break 3-3.
Lucky this time!
Did you have a back-up plan in case clubs did not break? How else might you make another trick?