Which expressions are perfect square trinomials? Select all that apply.
Ax^2 + 20x + 100
Bx^2 + 7x + 49
Cx^2 + 12x + 4
Dx^2 + 8x + 16
Ax^2 + 20x + 100
Bx^2 + 7x + 49
Cx^2 + 12x + 4
Dx^2 + 8x + 16