Hello. I need an advice about how to create new string array from 4 different string arrays:

We have 4 string arrays:

string[] arr1 = new string []  {"a1","a2","a3"..., "a30"};  
string[] arr2 = new string []  {"d10","d11","d12","d13","d14","d15"};  
string[] arr3 = new string []  {"f1","f2","f3"...,"f20"};  
string[] arr4 = new string []  {"s10","s11","s12","s13","s14"};  

We need to add all string elements of all 4 arrays with each other like this:

a1+d10+f1+s10  
a2+d10+f1+s10

...       
a1+d11+f1+s10  
a2+d11+f1+s10  
...  
a30+d15+f20+s14

I mean all combinations in that order : arr1_element, arr2_element, arr3_element, arr4_element
So the result array would be like that:
string[] arr5 = new string [] {"a1d10f1s10","a2d10f1s10 "....};

Any help would be good Thank you