Detailed Solution:
The correct answer is “All are correct”.
1) Western Uttar Pradesh, particularly the areas around Delhi, Noida, and Ghaziabad, has a higher concentration of industrial units compared to other regions in the state.
2) While relatively less industrialized compared to Western UP, Eastern UP does contribute around 20% of the state's industrial units.
3) Bundelkhand is known for its economic challenges and has historically been one of the most industrially backward regions in Uttar Pradesh.