Before they became a team, Richard Rogers and Oscar Hammerstein wrote a series of hit musicals in the 1950s and collaborating with other partners: Rogers with Lorenz Hart and Hammerstein with Jerome Kern.
A) Richard Rogers and Oscar Hammerstein wrote a series of hit musicals in the 1950s and collaborating
B) Richard Rogers and Oscar Hammerstein, whose series of hit musicals in the 1950s had collaborated
C) Richard Rogers and Oscar Hammerstein, who wrote a series of hit musicals in the 1950s, collaborating
D) Richard Richard Rogers and Oscar Hammerstein, who wrote a series of hit musicals in the 1950s and had collaborated
E) Richard Rogers and Oscar Hammerstein, who wrote a series of hit musicals in the 1950s, had collaborated