<?php
 
$data = $data = 'THE CORRECT ANSWER IS C.
    <p>
    Choice A Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industrys standard dummy text ever since the 1500s
    </p>
    <p></p>
    <p>
    Choice B Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industrys standard dummy text ever since the 1500s
    </p>
    <p>
    Choice D Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industrys standard dummy text ever since the 1500s
    </p>
    <p></p>
    <p>
    Choice E simply dummy text of the printing and typesetting industry.
    </p>
    <p></p>
    <p>
    <br>
    THIS IS MY MAIN TITLE IN CAPS
    <br>
    This my sub title.
    </p>
    <p>
    <br>
    TEST ABC: Lorem Ipsum is simply dummy text of the printing and typesetting industry. 
    </p>
    <p>
    <br>
    TEST XYZ: Lorem Ipsum has been the industrys standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. 
    </p>
    <p>
    <br>
    TES T TEST: It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. 
    </p>
    <p>
    <br>
    TESTXXX: It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.';
 
$dom = new DOMDocument();
$dom->loadHTML($data, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
$xpath = new DOMXPath($dom);
foreach($xpath->query('//text()') as $node) {
	$txt = trim($node->nodeValue);
	$p = $node->parentNode;
	if (preg_match("/^\s*(TEST ABC:|TEST XYZ:|TES T TEST:|TESTXXX)(.*)$/s", $node->nodeValue, $matches)) {
		// Put Choice X in bold:
		$p->insertBefore($dom->createElement('strong', $matches[1]), $node);
		$node->nodeValue = " " . trim($matches[2]);
	} else if (strtoupper($txt) === $txt && $txt !== '') {
		// Put header in bold
		$p->insertBefore($dom->createElement('strong', $txt), $node);
		$node->nodeValue = "";
	}
}
$data = $dom->saveHTML();
 
echo $data;
 
?>

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