The correct option is (d) <nobr>
Easiest explanation: <em> is same like <i></i>. It is emphasized text. <kbd> element is HTML Keyboard Input Element. <mark> element is for highlighting the text/paragraph. <nobr> is non-standard obsolete HTML element. This element prevents the text it contains from automatically wrapping across multiple lines. Resulting in the user having to scroll horizontally to see entire width of the text.
