Select the sentence that uses the idiom correctly.

Ranita was not selected for the job as she got cold feet.

The idiom "get cold feet" means to become afraid or hesitant to do something that you had previously agreed to do. So the sentence that uses the idiom correctly is (1) Ranita was not selected for the job as she got cold feet.

The other sentences do not use the idiom correctly.

• Walking bare feet on grass does not give someone cold feet.
• Getting too much exercise can make someone's feet cold, but it does not mean that they got cold feet.
• Swimming with cold feet is possible, but it is not easy.