Your trial build is not sufficiently advanced. The bar for trial builds is at or above the level of a 4 Bit ALU. Please respond with a new build if/when you decide on one.
On further inspection, seems you were referring to an RCA ALU as an RCA. Generally RCA just refers to a type of adder while ALU refers to a circuit which can do arithmetic and logic operations.
Generally along with OR and Flood Carry, we need it to be able to invert its inputs.