You are given a module my_dff with two inputs and one output (that implements a D flip-flop). Instantiate three of them, then chain them together to make a shift register of length 3. The clk port needs to be connected to all instances.
The module provided to you is: module my_dff ( input clk, input d, output q );
Note that to make the internal connections, you will need to declare some wires. Be careful about naming your wires and module instances: the names must be unique.
module top_module ( input clk, input d, output q );
wire q1,q2;
my_dff d1(clk,d,q1);
my_dff d2(clk,q1,q2);
my_dff d3(clk,q2,q);
endmodule