Let U$=\{1,2,3,4,5,6\}.$ Consider P$($U$)($a set of all subsets of U$)$ together with operation of union, intersection, and complement of a set, empty set as the zero and U as unit element in this Boolean algebra. In other words, boolean operation of addition $+$ is represented by $,*$ by $,$ and $\text{'}$ by taking a complement. If A $=\{1,6\},$ B$=\{6\},$ C$=\{1,2,3,5\}$ findA$+$B $=$ A$*$C $=$ A$*$C$\text{'}=$Please use the correct notation $($for example, if your answer is a set, indicate that with correct parentheses$),$ and do not insert any spaces in your answer.Which of those three operations: union, intersection, complement is unary? $($type your answer$)$