我需要一个div下推时，从一个dcc.dropdown菜单中的几个选项已被选中(破折号组件，python)

<div id="myDiv" style="height: 100px; background-color: #f2f2f2;"></div>

import dash
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Dropdown(
        id='dropdown',
        options=[
            {'label': 'Option 1', 'value': 'option1'},
            {'label': 'Option 2', 'value': 'option2'},
            {'label': 'Option 3', 'value': 'option3'}
        ],
        value='option1'
    ),
    html.Div(id='output-div')
])

@app.callback(
    dash.dependencies.Output('output-div', 'children'),
    [dash.dependencies.Input('dropdown', 'value')]
)
def update_output(value):
    if value == 'option1':
        return html.Div([
            html.H3('Option 1 selected'),
            html.P('This is the content for Option 1.')
        ])
    elif value == 'option2':
        return html.Div([
            html.H3('Option 2 selected'),
            html.P('This is the content for Option 2.')
        ])
    elif value == 'option3':
        return html.Div([
            html.H3('Option 3 selected'),
            html.P('This is the content for Option 3.')
        ])

if __name__ == '__main__':
    app.run_server(debug=True)