Android: cannot find symbol constructor Intent

package com.example;
 
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
 
 
public class Main extends Activity
{
    private Button but_opt_open, but_stat_open, but_stat_close;
    
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        /* -- open options buttons -- */
        but_opt_open = (Button)this.findViewById(R.id.but_opt);
        but_opt_open.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent opt_open = new Intent(this, options.class);
                startActivity(opt_open);
            }
        });

public class Main extends Activity implements OnClickListener{
 private Button but_opt_open, but_stat_open, but_stat_close;
   @Override
    public void onClick(View src) {
      Intent i = new Intent(this, options.class);
      startActivity(i);
    }
 
 
    public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);
       but_opt_open = (Button)this.findViewById(R.id.but_opt);
       but_opt_open.setOnClickListener(this);
    }
}

public class options extends Activity

implements OnClickListener