Choose the sentence with correct comma usage.

A- When Fredric Chopin was only six his talent as a pianist was obvious and he was
already composing original melodies.

B- When Fredric Chopin was only six his talent as a pianist was obvious, and he was
already composing original melodies.

C- When Fredric Chopin was only six, his talent as a pianist was obvious and he was
already composing original melodies.

D- When Fredric Chopin was only six, his talent as a pianist was obvious, and he
was already composing original melodies.