Given two noun phrases (arguments) and relationship between them, form a sentence that expresses theses arguments with the given relationship.

[EX Q]: Relationship: 'be head of', Argument/Subject 1: 'president', Argument/Subject 2: 'executive'
[EX A]: The service has been dubbed Derivatives Collateral Net and automatically aggregates and nets the overall collateral obligations of its participants , explains Art Certosimo , executive vice president and head of Broker-Dealer Services at the bank .

[EX Q]: Relationship: 'write for', Argument/Subject 1: 'lewi', Argument/Subject 2: 'new york time'
[EX A]: That decision prompted Paul Lewis , an English professor at Boston College , to write a letter to the New York Times in which he decried what he called " Frankenfood , " an innovation as misguided as Victor Frankenstein 's creation of his monster .

[EX Q]: Relationship: 'campaign for', Argument/Subject 1: 'hillary', Argument/Subject 2: 'obama'
[EX A]:
Hillary has been on the campaign trail for Obama .