Correct Answer:
B. Achieve two goals at once
The idiom "kill two birds with one stone" means to accomplish two different things at the same time or with a single effort. It implies efficiency and effectiveness in achieving multiple objectives simultaneously. For example, if you go to the grocery store to buy food and also pick up your dry cleaning on the way, you are "killing two birds with one stone." The idiom does not literally refer to harming animals, nor does it suggest being cruel, hunting, or doing nothing. It is a common expression used to praise smart planning and multitasking.