Which word could best replace either the underlined sentence or word in the paragraph?

“every dog has its day! ” it comes to those who are committed to their goals and never give up trying to achieve them. if you work hard and focus on what you want, eventually you will experience triumph. it’s only a matter of time before good things happen. that’s the advice my father gave to me, and i’m a firm believer in it.

a.
perfection

b.
knowledge

c.
success

d.
persistence