What subtitle did Street Fighter Alpha use in North America?

The North American subtitle for Street Fighter Alpha was Warriors' Dreams.

The full North American title is Street Fighter Alpha: Warriors' Dreams. Capcom released the arcade game in 1995 as the first all-new Street Fighter title after Street Fighter II. In Japan and several other regions, the same game was released under the title Street Fighter Zero, so the subtitle is also a useful clue that the question refers to the Western localization.

Street Fighter Alpha is a prequel to Street Fighter II and depicts younger versions of established characters. It also brings in fighters connected to the original Street Fighter and Final Fight, giving the game a roster and storyline positioned between those earlier titles and the World Warrior era.

The other options belong to different games or compilations. Double Impact refers to a Street Fighter III collection, Second Impact is part of Street Fighter III: 2nd Impact, and The New Challengers is the subtitle of Super Street Fighter II. Those names are easy to confuse because Capcom reused a broad pattern of subtitle-heavy releases throughout the series.