What is the convolution of the sequences of x1(n) = x2(n) = {1, 1, 1}?

• A. {1, 2, 3, 2, 1}
• B. {2, 1, 2, 3, 1}
• C. {1, 2, 3, 1, 2}
• D. {3, 1, 2, 3, 1}