Anyway , today I went to investigate the inside of the old cupboard and I found that the wall it has been standing up against all these years contains a kind of secret compartment . The weak wood of the cupboard back that gave way must have been a kind of entrance to this compartment . There was n't much in the compartment except some old pennies , part of an old candle , and two small leather - bound writing pads ( also very old but in good condition ) . When I opened the books I found that they comprised part of a carefully kept diary - indeed , my father 's own journal !
According to the above context, choose the best option to answer the following question.
Question: Why did they investigate the cupboard ?
Options:
- None of the above choices .
 - They were curious as to what is behind it .
 - They wanted to find the loose pennies .
 - They wanted to find their father 's old journal .


They were curious as to what is behind it .