The HTML commands that would help the developer to complete the task successfully are <h1>Upload Your Short Videos</h1> and <button>upload now</button>. The <h1> tag defines a heading level 1, which is the largest and most important heading on a webpage. The <button> tag defines a clickable button that can perform some action when clicked. The other options are not suitable for the task, as they either use the wrong tags or do not create a clickable button. The <span> tag defines a section of text with no specific meaning or formatting. The <p> tag defines a paragraph of text. The <hl> tag does not exist in HTML. Reference: HTML Tags - W3Schools