Choose the alternative which contains the reference to the pronoun in bold typeface in the sentence below, withdrawn from the text: "America's 16th...

Choose the alternative which contains the reference to the pronoun in bold typeface in the sentence below, withdrawn from the text: "America's 16th president certainly knew a lot about that."
a) The idea that the character of a man can be tested as he is given power.
b) The idea that any man can stand adversity.
c) The frustrations derived from the fact of not being an egomaniacal commander.
d) America.
e) America's 16th presidency.