Question Statement:
Read the following passage:
"Biochar, a carbon-rich solid produced via pyrolysis of biomass under oxygen-depleted conditions, possesses high specific surface area and a highly porous, aromatic carbon backbone. When incorporated into acidic weathered soils, biochar acts as a liming agent by releasing basic cations ($Ca^{2+}, Mg^{2+}, K^+$), elevating soil pH, reducing toxic exchangeable aluminum ($Al^{3+}$) concentrations, and enhancing the soil's moisture retention during dry spells."
Which of the following statements is/are DIRECTLY supported by the passage?
Options:
- (A) Biochar application helps increase the pH of acidic weathered soils.
- (B) Pyrolysis involves thermal degradation of biomass in the presence of abundant oxygen.
- (C) Biochar can reduce exchangeable aluminum toxicity in acidic soils.
- (D) Biochar improves soil water retention capacity during dry periods.