call vector in matrix with condition?

Let's say:

A=[1 2 3 10;4 5 6 15;7 8 9 20]
A=
   1     2     3    10
   4     5     6    15
   7     8     9    20

B=[5 6 15;8 9 20]
B=
     5     6     15    
     8     9     20

I want to call array C from A & B. How can?

C=[4;7]

[Guillaume]

What does call array C from A & B actually mean?

You need to explain why C is 2x1 and not some other size, and where the 4 and 7 are derived from A and B.

[ha ha]

@Guillaume . I just want to call the value from first column in matrix A, If the matrix in column 2:4 in A is equal to matrix B, respectively

Answer 1

[ha ha]

A(ismember(A(:,2:4),B,'rows'),1);

[M]

How does this correspond to A & B ?