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 !

Question: Why did they investigate the cupboard ?
Answer: 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 .