Mumbai, Jan. 29 -- India's industrial activity strengthened further in December, with the Index of Industrial Production (IIP) rising 7.8% year on year, marking the highest growth in over two years, data released by the National Statistical Office (NSO) on Wednesday showed. The December print follows a revised 7.2% growth recorded in November and signals a broad-based pickup in industrial momentum. Manufacturing, which carries the highest weight of 77.6% in the index, expanded 8.1% during the month, continuing to anchor the overall recovery. The sector was supported by strong output growth in basic metals, motor vehicles, and pharmaceuticals. As much as 16 out of 23 manufacturing industry groups registered positive growth during the month, ...