Explanation:

The city of Firozabad, located in Uttar Pradesh, is famously known as the 'Bangle City' or 'Glass City' of India. It is renowned for its extensive glass industry, particularly the manufacturing of glass bangles, which are exported worldwide. Option (1) Ceramics, (2) Ebony work, and (4) Wood work are crafts found in various parts of India, but they are not the primary or most famous industry associated with Firozabad. Moradabad, for instance, is known for brassware, while Saharanpur is known for wood carving. Thus, bangles are the defining product of Firozabad.