Compare four columns, give "yes" or "no" answer

Hello! This is my first time posting- I would like to thank everyone for all of the great answers. This time I can't seem to find exactly what I need on another thread, so I thought I would post my own.

I have the attached worksheet with clients' names in four columns (A-D). The first names and last names must remain separate. I need one additional column that shows whether a full name (first and last) in C and D also appears in A and B.

Then one more column that shows how many times the name in C and D shows up, but only if it is also in A and B.

I hope that isn't too confusing. Thanks!

Lauren