Final answer:
The Deckers saved Lisa's life by providing funds for Torvald's recovery in Italy.
Step-by-step explanation:
The Deckers saved Lisa's life by providing the necessary funds for Torvald to go to Italy where he could recover from his illness. However, Nora reveals to Mrs. Linde that Torvald and others believe that he recovered because of her father's financial help, but there is more to the story.