Underline a line in a Microsoft Word document using Microsoft.Office.Interop.Word

Tell me how to emphasize the line where the word was found?

var wordApp = new Word.Application(); wordApp.Visible = true; wordApp.Documents.Open(@"C:\Users\Администратор\Desktop\1.docx"); Word.Find findWords = wordApp.Selection.Find; findWords.Text = "Ключевое слово";