Cpt. alfred thayer mahan influenced the u. s. to

D:  build-up their Navy and become involved in world affairs.

Explanation:

His books on the importance on sea power in throughout history was instrumental in convincing the U.S. to spend more money in order to build-up their Navy and become involved in world affairs. Within the decade, the US would be involved in conflicts in Cuba and the Philippines.

the best description of postwar writers might be progressive.

following the war, writers showed a tendency to work on artistic or social matters rather than political themes. while postwar literature may not have been the greatest period of english literature, the themes provided excellent critics a high number of novels. such examples include anthony burgess, anthony powell and frank kermode, all of which can be placed under the progressive view.