After giving nearly 5,000 people a second chance at life, doctors are celebrating the 25th anniversary of Britian's first heart transplant which was performed at Cambridgeshire's Papworth Hospital in 1979.

Based on that paragraph can we conclude that this sentence is true?
Britian's first heart transplant which was performed at Cambridgeshire's Papworth Hospital before 1980.

Options are:
(i). Yes.
(ii). It's impossible to say.
(iii). No.