According to the HTML5 specification, this structure satisfies the criteria for mandatory selection:
required attribute is specified.
The field does not have multiple attribute specified (indicating it's not for multiple selections).
The display size is assumed to be 1 (since no size attribute is specified).
The first option element has an empty value (in this case, "Please select").
The first option element is a direct child of the element (not part of an optgroup).
By adhering to these conditions, the required attribute becomes functional for fields, ensuring that the user makes a selection before submitting the form.
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