1.
Only a. is true.
2.
The blue region is what you want.
3.
(U∩A)∩(Φ∪A')
By identity law, (U∩A)=A
=>A∩(Φ∪A')
By identity law, (Φ∪A')=A'
=>A∩A'
By complement law
=> A∩A'=Φ
=>(U∩A)∩(Φ∪A') =Φ
4.
∣A∪B∪C∣= ∣A∣+∣B∣+∣C∣-∣A∩B∣-∣B∩C∣-∣A∩C∣+∣A∩B∩C∣
= 9