Many immigrants in late 19th century american began to reject the tradition of arranged marriages and embraced more american nation of ...

A. Dating

B. Romantic Love

C. Living Single

D. Employing a Matchmaker

Romantic Love.

Explanation:

It isn't either C or D. Matchmakers are unheard of in America by Americans born in the US (or most of them reject matchmakers.)

No society that was governed by tradition wanted to live singly.

Dating was very traditional. It was also heavily chaperoned. That wouldn't be far from the customs of other nations.

I think the answer you want is romantic love.