Hint:Idioms are an expression in the use of a language which is unique to itself, because it has a meaning which cannot be derived from the standard meanings of its elements.
“To have an easy with it” refers to an experience something less difficult or more serious than others have experienced. Let us look at an example for understanding it better.
“She hasn't had an easy time of it since Jack left.”
Let us go through the meaning of the idioms given as options to find the option which best expresses the meaning of the idiom “To have an easy of it.”
>To squander away resources: It refers to the using or failing to use any tool in an inefficient, unnecessary or careless manner. Let us look at an example here for better understanding.
“Fred squandered away all his resources in a gambling game”
>To indulge in frivolities: It refers to the state of being ignorant. The situation where the person concerned is acting dumb or not paying any importance to a certain thing. Let us look at an example.
“He has no time for indulging in frivolities”
>To take the world lightly: It refers to the state of looking at something without much seriousness or to be really casual or carefree about something. Let us look at an example here.
“He takes the world very lightly regardless of the problems he has been facing.”
>To be self-dependent: It refers to a state of being self-reliant or taking no help from others for living one’s life fruitfully. Let us look at an example here.
“She was becoming more self-dependent as days went by”
>To live in quiet and comfort: It refers to a situation in which the concerned person is living in a settling situation or a state in which one has no disturbances or stress. From this meaning we can see that it is the correct answer. Let us look at an example here.
“Everyone has a dream of living in quiet and comfort”
Note: You might get confused with option b. But to clear your thoughts and to get the correct answer, you can always take the help of the internet or any book on idioms and phrases.