I will try my best.
1. To improve how people live
2. A constraint
3. Test product safety
4. None of the above.
Sorry if any of them are wrong.
Answer:
D) The presence of additional Br- ions already in the solution means equilibrium will be reached when much less CuBr has dissolved.
Explanation:
CuBr ⇄
+ 
Because there is Br- in CuBr, when put into solution, those Br- ions become part of the products side of the equation, shifting the equilibrium back towards the CuBr side, meaning less CuBr will dissolve.
Hi i think its the the 3rd one