Simple OptGroup test.

The following SELECT element should have three sentences, numbered 1, 2 and 3:

This is sentence 1. This is sentence 3.

If any line has the same sentence repeated twice then there is a bug.

See also:

• Simple OPTGROUP test.
• Simple OPTGROUP optional end tag test.
• Complex OPTGROUP test.
• Simple OPTION test.
• SELECT test.
• SELECT size test.