Are PHP constants case-sensitive?
Are PHP constants case-sensitive?
PHP constants are case-sensitive by default. However, using the define() function, it is possible to create case-insensitive constants by passing a third parameter set to true. This feature has been deprecated as of PHP 7.3, but it is still accurate to say that they can be case-insensitive up to that version.
Response A is the correct. https://www.php.net/manual/en/function.define
A is correct, by default are case-sensitive, but with define you can create case-insensitive constants passing a third param
response B is correct
Correct answer is A
Case insensitive in define() is deprecated since 7.3. Maybe that's why the correct answer is C. For PHP <7.3 the correct answer is A.