Final answer:
The data suggest that air pollution negatively affects chlorophyll levels in plants, which leads to a decrease in photosynthesis, rather than showing signs of adaptation or increased cellular respiration.
Step-by-step explanation:
The data presented suggest that air pollution has a negative effect on chlorophyll in plants, which is integral to the process of photosynthesis. Given that chlorophyll a and b are essential for absorbing light and converting it into chemical energy, a reduction in chlorophyll due to air pollution would likely lead to a decrease in photosynthetic activity, photosynthesis decreases in response to air pollution. The other options, such as gene expression not being affected, plants adapting, or an increase in cellular respiration in response to pollution, are not directly supported by the data provided. The data indicate that the effects of pollution are detrimental to plant health and do not suggest an adaptive or compensatory response in terms of increased cellular respiration or gene expression changes.