Born in new york in 1856, louise blanchard bethune is considered the first woman architect.
the underlined phrase is?
participial
gerund
infinitive

If the underlined phrase is born in New York in 1856, then that would be a participial phrase, which often functions as an adjective in a sentence, like is the case here.
Gerund is always used as a noun, and infinitive has the form to + verb (to go, to be...)

It's B, because the others don't make sense.