The correct option is A made
To "accumulate" is to gather together. Here, "made" in option A is the best answer as it implies gaining a fortune or earning money.
"Expanded" means making something larger. There is nothing in the context to indicate that he already had a fortune, so he could not possibly have expanded it.
"Concentrated" means wholly directing to one thing. This is an antonym of expanded.
"increased" is incorrect due to the same reason as expanded is. There is nothing in the context to indicate that he already had a fortune, so he could not possibly have increased it.