A frog egg cell has a diameter of $2.5\,\text{mm}$. A human egg cell has a diameter of $120\,\mu\text{m}$. Which value indicates approximately how many times bigger a frog egg cell is than a human egg cell?
- A$\times 2$
- B$\times 21$
- C$\times 48$
- D$\times 300$