$\text{A.}1\frac{N}{c{m}^2}=1\frac{N}{1cm\cdot 1cm}=1\frac{N}{\frac{1}{100}m\cdot \frac{1}{100}m}=1\frac{N}{\frac{1}{10000}{m}^2}=1\cdot 10000=10000\frac{N}{m^2}$