Write the Sentence as a Proportion Using $x$ As the Variable $x = 1$

Multiple Choice

Write the sentence as a proportion using $x$ as the variable. Solve the proportion to answer the question. 80% of what number is 80?

A) $x = 1$
B) $x = 64$
C) $x = 100$
D) $x = 640$
E) $x = 110$