A flock of swans got…

A flock of swans got down to a beach where a solitary crow was hopping around. The crow watched them with disdain.
‘How gracelessly you fly!’ he said to the swans. ‘All you know is how to flap your wings. Can you glide? Can you somersault in the air? No, that’s beyond you. Let’s have a flying competition. I’ll show you what flying really is!’
The swan agreed. He launched himself into the air and began flying over the sea. The crow flew after him, making all sorts of derisive comments about his manner of flying.
On and on they flew till finally the land was lost to sight. Water stretched endlessly on all sides. The crow’s comments became less and less frequent and finally stopped altogether. He had begun to tire. Eventually he became so tired that he found it hard to stay in the air. He had to struggle to keep from falling into the water.
The swan, pretending to be unaware of his plight, said, ‘Why do you keep touching the water, brother? Is that another flying maneuver?’
‘No,’ squawked the crow, the fight completely gone out of him. ‘I’m in trouble… a curse on my boasting! If you do not come to my aid, I’ll drown…’
The swan had pity on the crow and took him on his shoulders flying back to the shore.

Which of the following are the problems and the solutions according to the story?
I. The crow challenged the swan to fly. — The swan showed the flying maneuver.
II. The crow almost plunged into the sea. — The swan saved the crow before drowning.
III. The swan couldn’t stand to be disrespected. — The swan accepted the crow’s challenge to wing.
IV. The swan didn’t realize the crow’s trouble. — The crow squawked asking for the swan’s assistance.