Correct Option (B)
The passage describes a process where carbon dioxide (CO₂) is injected into basalt rocks, leading to its chemical conversion into limestone. This geological process effectively immobilizes CO₂ by transforming it into a stable mineral form. This mechanism directly aligns with the concept of carbon sequestration, which involves capturing and storing atmospheric carbon dioxide to mitigate climate change. Therefore, the most logical, rational, and practical implication is its utility as a method for carbon sequestration.
Incorrect Options:
Option (A): The passage focuses on the environmental outcome of converting CO₂ into stone, not on the commercial production of limestone for construction purposes. The scale and economics for building material production are not discussed or implied.
Option (C): While the process involves the dissolution of calcium and magnesium from basalt, the passage does not suggest that this method is intended to make basalt a source for extracting these minerals. Their role is described as reactants in the CO₂ conversion process.
Option (D): The acidic mixture formed by carbon dioxide and water is an intermediate step in the described chemical reaction that leads to limestone formation. The passage does not imply that the primary purpose or a practical suggestion is the production of rock-dissolving acid for other applications.