Selecting a particular Index in dropdown menu (twig)

5 

                         
                            <div class="field select-box">
                                <select name="package" data-placeholder="Select Your Preferred Package">
                                    <option>Select One</option>

                                    {% set selectedPlan = "10000" %} // declare a twig variable to behave as value from controller

                                    <option value="5000"{% if selectedPlan == "5000" %} selected="selected"{% endif %}>
                                        Basic Plan - ₦5,000
                                    </option>
                                    <option value="10000"{% if selectedPlan == "10000" %} selected="selected"{% endif %}>
                                        Advanced Plan - ₦10,000
                                    </option>
                                    <option value="20000"{% if selectedPlan == "20000" %} selected="selected"{% endif %}>
                                        Professional Plan - ₦20,000
                                    </option>

                                </select>


                                <i class="fa fa-sort"></i>
                                {% if errors.package %}
                                    <span style="color: #ffffff;" class="help-block">{{ errors.package | first }}</span>
                                {% endif %}
                            </div>

but it doesn’t works.