The Earth takes approximately 365.25 days to revolve around the Sun. To account for the time beyond 365 days, we add a
day to the calendar

It takes approximately 365.25 days for Earth to orbit the Sun — a solar year. We usually round the days in a calendar year to 365. To make up for the missing partial day, we add one day to our calendar approximately every four years. That is a leap year.

It’s b. mass i searched it up

The molar mass of a substance is defined as the mass of 1 mol of that substance, expressed in grams per mole, and is equal to the mass of 6.022 × 10 23 atoms, molecules, or formula units of that substance.