Select the most appropriate meaning of the given idiom.

To fish in troubled waters

To take advantage of a difficult situation

The most appropriate meaning of the idiom "to fish in troubled waters" is to take advantage of a difficult situation.

The other options are incorrect.

• "To try to find a big catch in the deep sea" is not the same as to fish in troubled waters. Trying to find a big catch in the deep sea is simply a fishing term, while to fish in troubled waters is a figurative expression.
• "To try to do something that is very difficult" is not the same as to fish in troubled waters. Trying to do something that is very difficult is simply a challenging task, while to fish in troubled waters is a way of saying that someone is trying to take advantage of a difficult situation.
• "To catch fish in stormy weather in the sea" is not the same as to fish in troubled waters. Catching fish in stormy weather in the sea is simply a dangerous fishing practice, while to fish in troubled waters is a figurative expression.

The idiom "to fish in troubled waters" comes from the idea that fish are more likely to be caught when the water is disturbed. So, when someone is said to be fishing in troubled waters, it means that they are trying to take advantage of a difficult situation. For example, you might say "The politician was accused of fishing in troubled waters by taking advantage of the economic crisis."