Because the United States had gained control of Guam, Hawaii, Puerto Rico, and the Philippines, Alfred T. Mahan supported what policy at the end of the 19th century?
OA
an expansion of the American navy
ОВ.
the use of economic coercion in Asia
OC.
a contraction of the American military

OA - An expansion of the American navy

Explanation:

By arguing that sea power—the strength of a nation’s navy—was the key to strong foreign policy, Alfred Thayer Mahan shaped American military planning and helped prompt a worldwide naval race in the late 19th and early 20th centuries. Mahan studied at Columbia for two years beginning in 1854—he was a member of the Philolexian Society, the campus literary club established in 1802—before decamping for Annapolis, from which he graduated in 1859. A longtime naval officer who cut his teeth on the Union side in the Civil War, Mahan eventually lectured on history and strategy at the Naval War College in Newport, R.I. It was there, inspired in part by a history of Rome, that he began developing his theories; in 1890 he turned his lecture notes into The Influence of Sea Power upon History, 1660-1783.

a, c, & d are correct:

they wanted lands to settle the extra population.

they wanted new markets for english goods.

they wanted to avoid civil war.

the use of email to replace slower surface mail.