Form compound nouns.

Solution:

Forming compound nouns:

• 1. foot - a fish (footfish - unlikely, more likely foot - b phone -> phone booth; 2. book - b phone -> bookshop; 3. smart - c ball -> smart card; 4. gold - d store -> gold store. Given the options, it's most likely: 1. foot - not forming a common compound with given options. Assuming a typo and it meant something else or the options are not exhaustive. If we *must* use the options: foot-ball (c), book-store (d), smart-phone (b), gold-fish (a). Let's re-evaluate based on common compounds and the provided options. The numbers on the left seem to correspond to the list of words, and the letters on the right to the second word of the compound. However, the image doesn't explicitly state this mapping. Assuming the typical structure for this type of question:
• 1. foot + ball = football (c)
• 2. book + store = bookstore (d)
• 3. smart + phone = smartphone (b)
• 4. gold + fish = goldfish (a)

Answer: 1-c, 2-d, 3-b, 4-a.