The maximum acceptable concentration of nitrogen dioxide is 0.1ppm. What is the acceptable concentration of nitrogen dioxide in parts per thousand and parts per hundred?

a. Parts per thousand: 1.0 ppt, Parts per hundred: 0.01 pph
b. Parts per thousand: 0.001 ppt, Parts per hundred: 0.01 pph
c. Parts per thousand: 0.1 ppt, Parts per hundred: 1.0 pph
d. Parts per thousand: 0.01 ppt, Parts per hundred: 0.1 pph