Answer:
The first option:
yellow shirt, white trouser
yellow shirt, black trouser
green shirt, white trouser
green shirt, black trouser
Step-by-step explanation:
To find the possibilities, you would see that you would have two yellow shirts and two green shirts with different trousers, so you can eliminate the bottom two. And because there will be two of each shirt with defferent trousers, it will be the same for trousers: two of each trouser will be in the possibilities. The only one that fits this description, is the first one.
yellow shirt, white trouser
yellow shirt, black trouser
green shirt, white trouser
green shirt, black trouser
