The correct option is "1 and 2 only." The first statement is accurate because the Consumer Price Index (CPI) gives greater weight to food items as it reflects the consumption patterns of households, which heavily rely on food purchases. The second statement is also correct, as the WPI primarily focuses on the prices of goods (especially commodities) and does not account for services, while CPI includes both goods and services, thus providing a broader perspective on consumer expenditures. The third statement is incorrect; the Reserve Bank of India primarily uses the CPI as its key measure of inflation for monetary policy decisions, as it better reflects the actual cost of living and inflation experienced by consumers.