Hello. You forgot to show the text to which this question refers. The text is: 
Are you, are you 
Coming to the tree 
Where they strung up a man they say murdered three. 
Strange things did happen here 
No stranger would it be 
If we met up at midnight in the hanging tree. 
 
Are you, are you 
Coming to the tree 
Where the dead man called out for his love to flee. 
Strange things did happen here 
No stranger would it be 
If we met up at midnight in the hanging tree. 
 
Are you, are you 
Coming to the tree 
Where I told you to run so we’d both be free. 
Strange things did happen here 
No stranger would it be 
If we met up at midnight in the hanging tree. 
 
Are you, are you 
Coming to the tree 
Wear a necklace of rope, side by side with me. 
Strange things did happen here 
No stranger would it be 
If we met up at midnight in the hanging tree.
Answer:
 b. Unpopular events or activities were done here. 
Step-by-step explanation:
The poem shows a series of different situations that address unpopular events, which are unusual and often peculiar. According to the poem, the place near the tree is a strange place that attracts peculiar situations with little explanation and a lot of complexity of reasoning, which can even intrigue readers and listeners.