Which of the following best describes why an island location, such as the mauna loa observatory in hawaii, is an ideal location to measure global co2 concentrations?

the island is also a dormant volcano, so there will be only anthropogenic atmospheric co2 measured at the site.

a

the location is below the inversion layer, making it less prone to local effects from industry and transportation.

b

the location is far from any continent, providing atmospheric air samples that are less likely to be affected by industry and transportation.

c

the impact of primary producers in the surrounding pacific ocean is negligible, reducing the effect of photosynthesis and respiration on co2 levels.