One sheet of aluminium foil is folded two times so that a pile of four sheets is formed. The measured total thickness of this pile is $(0.80 \pm 0.02)\,\text{mm}$. A digital calliper with a zero error of $(-0.20 \pm 0.02)\,\text{mm}$ is used for the measurement. What is the percentage uncertainty in the calculated thickness of one sheet?
- A$1.0\%$
- B$2.0\%$
- C$4.0\%$
- D$6.7\%$