Please answer need help for a quiz

ranks (& how to earn them):

-beginner (needs at least 0 points & 0 brainliest answers)

- hand (needs at least 100 points & 0 brainliest answers)

-ambitious   (needs at least 250 points & 0 brainliest answers)

-virtuoso (needs at least 500 points & 5 brainliest answers)

-expert   (needs at least 1,000 points & 10 brainliest answers)

-ace (needs at least 3,000 points & 15 brainliest answers)

-genius   (needs at least 15,000 points & 50 brainliest answers)

how to award brainliest:

you must wait until 2 people answer to award brainliest. i'm pretty sure that it should be next to the "" and "comments" buttons.  

since no one answered yet i will give it a shot, not completely sure tho.

i think it should be y=cos(x+2pi), (third answer, answer c)

good luck.