What should be done to accept an offer through a checkbox?

The correct answer is to tick the box, as it directly corresponds to the action required to accept an offer via a checkbox. When prompted with a checkbox in an online form or agreement, ticking the box signifies your acceptance of the terms or the offer presented. This action serves as a visual confirmation that the individual agrees to what is being provided or proposed.

The other options involve actions that are not necessarily linked to the specific act of accepting an offer through a checkbox. For instance, submitting a form often follows the action of ticking the box but does not encompass acceptance on its own. Paying a fee may be unrelated to the checkbox itself, as acceptance does not inherently require a financial transaction. Contacting support could be relevant if there are issues or questions regarding the offer, but it does not fulfill the requirement of formally accepting an offer as indicated by the checkbox. Therefore, ticking the box is the most straightforward and appropriate action to indicate acceptance.