You want to create a simple click-to-call link on your mobile Web page. Which line of HTML would add this feature?

You want to create a simple click-to-call link on your mobile Web page. Which line of HTML would add this feature?

• A. <a href="mailto:18005551212"> Call Us Now </a>
• B. <a href="sms:18005551212"> Call Us Now </a>
• C. <a href="http://tel:18005551212"> Call Us Now </a>
• D. <a href="tel:18005551212"> Call Us Now </a>

Answer: (D)

To enable click-to-call on a mobile page, use the tel: URI scheme in the link. This tells the device to open the phone dialer with the number pre-filled, so a user can simply tap to initiate the call. The line that correctly does this is the one with href="tel:18005551212" and visible text like "Call Us Now." Why this is best: tel: is the standard way to request a phone call from a webpage. It directly invokes the dialer with the specified number, which is exactly what a click-to-call feature needs. Why the other options don’t fit: using mailto opens an email client, not a call; sms would start a text message; and http://tel: attempts to treat the tel: URI as a web resource, which won’t trigger a call.

To enable click-to-call on a mobile page, use the tel: URI scheme in the link. This tells the device to open the phone dialer with the number pre-filled, so a user can simply tap to initiate the call. The line that correctly does this is the one with href="tel:18005551212" and visible text like "Call Us Now."

Why this is best: tel: is the standard way to request a phone call from a webpage. It directly invokes the dialer with the specified number, which is exactly what a click-to-call feature needs.

Why the other options don’t fit: using mailto opens an email client, not a call; sms would start a text message; and http://tel: attempts to treat the tel: URI as a web resource, which won’t trigger a call.