In $1999,$ LEGO Star Wars products were released on the wings of the blockbuster The Phantom Menace, becoming one of the most successful product launches not only for LEGO but also for the global toy industry. In the $2000$s$,$ more than one$-$sixth of LEGO Groups' earnings came from the Star Wars line. What was this initiative between LEGO and Star Wars called?

a$.$ subsidiary initiative

b$.$ solution$-$based initiative

c$.$ headquarters initiative

d$.$ customer$-$focused initiative