NEW DELHI: Headline inflation dropped to its lowest in three years in December, reinforcing expectations that the Reserve Bank of India will cut rates at its policy review on January 29 to boost the economy, which is headed for its worst showing in a decade. The inflation numbers are the latest piece of data providing backing to those, notably the finance ministry, calling for a cut in interest rates after a fall in industrial output in November reported on Friday. Exports too shrank in December, indicating that the Asia's third-largest economy was close to stalling.