In what way did the purchase of Alaska fit with Secretary of State William Seward’s foreign policy toward Asia?

ASeward thought the purchase of Alaska could protect the United States from Asian aggression.
BSeward thought that Alaska could be a stepping stone to increased trade with Asia.
CSeward thought the purchase of Alaska would weaken Japan and other Asian powers.
DSeward thought the purchase of Alaska would make it possible to annex Midway Island.

Verified Answer :

In what way did the purchase of Alaska fit with Secretary of State William Seward’s foreign policy toward Asia? 

B. Seward thought that Alaska could be a stepping stone to increased trade with Asia.

Purchasing Alaska in 1867 became a stepping stone for the United States to rise as a power in the Asia-Pacific. It gave them the access to the Pacific northern rim.