module safe_mux2 (
input [7:0] a,
input [7:0] b,
input sel,
output reg [7:0] y,
output reg sel_unknown
);
always @* begin
y = 8'h00;
sel_unknown = 1'b0;
// if `sel` is 0
if (sel === 1'b0) begin
// Write your code here
y=a;
end
// else if `sel` is 1
else if (sel === 1'b1) begin
// Write your code here
y=b;
end
// `sel` is either `x` or `z`
else begin
// Write your code here
y=8'h00;
sel_unknown=1;
end
end
endmodule