Answer to Question 1
Jetties and groins are beneficial for widening beaches and preventing erosion on portions of the beach that are up-current. However, jetties and groins disrupt the longshore drift, so areas downcurrent from these features become starved for sediment and experience erosion.
Seawalls are largely effective at stopping erosion in the areas where they are built, however construction is expensive to build and maintain. They can be damaged in storms and cause greater erosion in adjacent areas not protected by seawalls.
Beach nourishment will temporarily widen a beach, however, erosive processes will typically carry the renourished sand out to sea during winter. Renourishment is also costly.
Are these viable permanent solutions? Answers will vary and should be graded on the strength of the justification.
Answer to Question 2
A