How do you plan to solve it?
module selector3 (y, a, b, c, sel); input [7:0] a, b, c; input [1:0] sel; output reg [7:0] y; always @(*) begin if (sel==2'b00) y=a; else if (sel==2'b01) y=b; else if (sel==2'b10) y=c; else y= 8'h00; end endmodule