The correct statement is D, because it uses the SOSL syntax to search for the phrase 'ACME' in all fields of the Contact and Lead objects, and returns a list of sObjects that match the criteria. The other statements are incorrect because:
* A uses the SOQL syntax, which can only query one object at a time, and the LIKE operator requires a wildcard character (%) before and after the search term.
* B uses the SOSL syntax, but returns a list of lists of sObjects, which is not the expected output.
* C uses the SOSL syntax, but returns a map of sObjects, which is not the expected output. References:
* SOSL Syntax - Salesforce
* SOSL Statements - Salesforce
* SOQL and SOSL Reference - Salesforce