Final answer:
John Lennon performed at the Sweet Toronto Peace Festival with the Plastic Ono Band, marking his first live performance separate from The Beatles.The correct option is C.
Step-by-step explanation:
The artist who performed at the Sweet Toronto Peace Festival is John Lennon.
The festival, also known as Toronto Rock and Roll Revival, was held on September 13, 1969, and among the various performers, John Lennon appeared with the Plastic Ono Band, which was his and Yoko Ono's new group at the time.
This concert notably featured John Lennon's first live performance separate from The Beatles.
While artists like Bob Dylan or Eric Clapton are well known for their contributions to music and have performed at many concerts and festivals, they did not perform at this particular event. The correct answer to the question is c) John Lennon.