Office-ui-fabric Dropdown shows no item

Question

I'm working on a SharePoint Webpart and I have a Dropdown, which works fine, but when I reload the page, it shows no item in the dropdown field. When I open the list and select some item, it will be presented.

and

I want to reset the Dropdown to default valu " * Bitte wählen." How is it possible? I have a Description Text under my list, and I can reset it.

Here is my code too:

      <div className={styles.choice}><br></br>
        <Dropdown options={ this.state.options }
                  onChange={ this.handleChange }/>  
      </div>

      <textarea id= "infoText"  readOnly value={this.state.selectedValue} className={styles.infoText} placeholder= "Option aus der Rubrik wählen"></textarea>


 public handleChange = (event: FormEvent<HTMLDivElement>, option: IDropdownOption): void => {
this.setState({
  selectedOption: option.text,
  selectedValue: option.key.toString()
});

}

public addListItem = ():void => { let dropdown = option.text; // item push in the SharePoint List pnp.sp.web.lists.getByTitle("TestList") .items.add({ 'Rubrik': dropdown }) .then(()=> alert("Die Datei wurde erfolgreich gespeichert!")); } }
}

Any Idea? Thank you!