Answer: The first option
Explanation: In HTML, tags are used to classify the format of text between them. The correct usage of a tag is shown in the first option, with the first tag, <h1>, proclaiming that the following text is a part of the first header (hence h1), and the second tag proclaiming the conclusion of the first (the forward slash before the h1 in the second tag shows that the first tag is being concluded, and no text past that point pertains to the tags).