• Tomato and bell pepper are typical C3 plants. Under current ambient atmosphere (approx. $420\text{ ppm } CO_2$), the primary carboxylating enzyme Rubisco is not CO2-saturated and exhibits significant oxygenase activity (photorespiration).
• When grown in greenhouse environments enriched with CO2 (up to $800–1000\text{ ppm}$), the carboxylation rate of Rubisco increases sharply while photorespiration is suppressed.
• This results in an increased net photosynthetic rate, enhanced assimilate production, and substantially higher economic fruit yields (the CO2 fertilization effect), confirming Option 2.

• Statement I is incorrect: Approximately 90% of atmospheric ozone resides in the Stratosphere (the beneficial 'ozonosphere' at 15–35 km altitude absorbing harmful UV-B radiation), while only about 10% is present in the Troposphere as a secondary air pollutant and greenhouse gas.
• Statement II is correct: In the IPCC Fourth Assessment Report (AR4, 2007), the globally averaged radiative forcing due to increases in tropospheric ozone since 1750 was estimated at $+0.35 \pm 0.15 \text{ W}\cdot\text{m}^{-2}$, ranking it as the third most important greenhouse contributor after $CO_2$ and $CH_4$.
• Therefore, Statement I is incorrect but Statement II is correct, confirming Option 4.

Analysis of environmental statements:

• Statement 2 is incorrect (wrong): Stratospheric ozone ('good ozone' in the upper atmosphere) acts as a protective shield absorbing harmful solar UV-B radiation, safeguarding animals and plants from skin cancers, cataracts, and cellular damage. Only tropospheric ozone ('bad ozone' at ground level) is toxic and harmful.
• Natural greenhouse effect maintains Earth's surface temperature at a hospitable $\sim 15^\circ\text{C}$ (without it, temperature would be $-18^\circ\text{C}$).
• Natural eutrophication is the natural aging process of lakes over geological timescales.