CTET 2 Social and Science 27 Dec 2021 Paper

Which of the following statements is/are correct?
a. Earth takes 365$\frac{1}{4}$ days to revolve around the sun.
b. We consider a year as consisting of 365 days only and ignore six hours for the sake of convenience.
c. Every fourth year, February is of 28 days instead of 29 days.