In this task you need to give reasons to justify the pronoun coreference relations. Each of the provided inputs contains a sentence with a target pronoun and a question about how to justify the coreference between a noun phrase and the target pronoun. Good practices involve the discussion about how the descriptions attached to the targeted pronoun relate to the noun phrase candidate in the question. The reasoning could come from one or multiple following knowledge types about commonsense: First: 'Property', the knowledge about property of objects (e.g., ice is cold). Second: 'Object', the knowledge about objects (e.g., cats have ears). Third: 'Eventuality', the knowledge about eventuality (e.g., 'wake up' happens before 'open eyes'). Forth: 'Spatial', the knowledge about spatial position (e.g., object at the back can be blocked). Fifth: 'Quantity', the knowledge about numbers (e.g., 2 is smaller than 10). Sixth: all other knowledge if above ones are not suitable. Write the sentence in natural language.

Sentence: My meeting started at 4:00 and I needed to catch the train at 4:30,  so there wasn't much time. Luckily, it was delayed, so it worked out.
 Question: Why does the 'it' refer to the train?
Because the code word is been used to make it in a change so it is been done in a public spot to decrease attention.

Sentence: Frank was upset with Tom because the toaster he had sold him didn't work.
 Question: Why does the 'he' refer to tom?
Because he upset due to toaster sold.

Sentence: Joan made sure to thank Susan for all the help she had recieved.
 Question: Why does the 'she' refer to joan?

Because Joan was thanking Susan for helping her.