StringBuilder

Which of the following StringBuilder's contain a text fully equal to "Behold the power of StringBuilder"?

StringBuilder sb1 = new StringBuilder();
sb1 = sb1.append("Behold the power of StringBuilder");

StringBuilder sb2 = new StringBuilder();
sb2.append("Behold the power of StringBuilder");

StringBuilder sb3 = new StringBuilder()
        .append("Behold")
        .append("the power of")
        .append("StringBuilder");

StringBuilder sb4 = new StringBuilder("Behold the power of StringBuilder");