Which of these sentences exhibits proper usage?

a. leonardo da vinci's “mona lisa” is probably the most famous painting in the world.
b. leonardo da vinci's, mona lisa, is probably the most famous painting in the world.
c. leonardo da vinci's “mona lisa” is probably the most famous painting in the world.
d. leonardo da vinci's mona lisa is probably the most famous painting in the world.

The sentence that exhibits proper usage is D. Leonardo da Vinci's Mona Lisa is probably the most famous painting in the world.

Explanation:

This sentence exhibits proper usage because Mona Lisa, that is a painting, is not between quotation marks. Titles of paintings, drawings, statutes, photographs or any other works of art should not be between quotation marks.

In any case, Mona Lisa could be italicized, like this: Leonardo da Vinci's Mona Lisa is probably the most famous painting in the world.

explanation:

hitler's  "rise" can be considered to have ended in march 1933, after the reichstag adopted the enabling act of 1933 in that month. president paul von hindenburg had already appointedhitler  as chancellor on 30 january 1933 after a series of parliamentary elections and associated backroom intrigues.

b. the right to wage war and make peace