As a foursome they were a group about 1970-71.
They formed in 1970 and released their first single in 1972.
in September 1975
Ring Ring was released in 1972.
ABBA first Album is the Ring Ring album.
Since the question doesn't specify 'first what' I will have to say their first hit was Ring Ring in 1972.
Sweden.
They came from Sweden, Europe.
Sweden
The foursome we now know as ABBA first began to be noticed in 1972.
The members of ABBA first performed together in 1970 but released their first chart single in June of 1972 and adopted the name ABBA later that summer.
no
Stockholm, the capital city.