How did the “island-hopping” strategy save American lives in World War II?

How did the “island-hopping” strategy save American lives in World War II?

a. US forces did not attack Japanese-held islands with no strategic importance.
b. Allied forces attacked Japanese-held island by sea and air only.
c. US forces attacked Japanese-held islands with weak defenses.
d. Allied forces attacked different islands, sharing the losses equally.