You are developing a customer web form that includes following HTML.
<input id= "textAccountType"/>
You need to develop the form so that customers can enter only a valid account type consisting of two English alphabet characters.
Which code segment should you use?

Correct Answer: B
Explanation/Reference:
Explanation:
HTML <input> pattern Attribute
The pattern attribute specifies a regular expression that the <input> element's value is checked against.
Example
An HTML form with an input field that can contain only two letters (no numbers or special characters):
<form action="demo_form.asp">
Country code: <input type="text" name="country_code"
pattern="[A-Za-z]{2}" title="Three letter country code"/>
<input type="submit"/>
</form>
Reference: HTML <input> pattern Attribute
http://www.w3schools.com/tags/att_input_pattern.asp