D) Calculate how much money Wendy has to start with (This should be $24 as her sister had $12 so twice $12 is $24). Add up the money she spent ($4 at the market and $3 at the newspaper store, this is $7). Subtract the amount Wendy spent from the amount she started with ($24-$7=$17).
There for Wendy had $17 left and D is the best one to use to solve this problem! Hope this helped!