Final answer:
D) Giuseppe Mazzini. Giuseppe Mazzini is the leader who said "the main thing is to make history, not to write it." He was a prominent Italian nationalist and a key figure in the Young Italy movement.
Step-by-step explanation:
The leader who is quoted as saying "the main thing is to make history, not to write it" is Giuseppe Mazzini. Mazzini was an Italian nationalist and one of the great thinkers of the Young Italy movement in the 19th century. He believed in the power of nations emerging organically to replace conservative monarchies and oppressive influences. However, his hopes for a united Italy were dashed when conservative kings regained power during the Revolutions of 1848.