By Nate Raymond BOSTON (Reuters) -The architect of the largest U.S. college admissions fraud scheme ever uncovered was sentenced on Wednesday to 3-1/2 years in prison for helping wealthy parents secure the admission of their children to elite universities through cheating and bribery. William “Rick” Singer, a former college admissions consultant who played a key role as a cooperating witness in the “Operation Varsity Blues” investigation, was sentenced by U.S. District Judge Rya Zobel in Boston. Singer, 62, admitted in 2019 to facilitating cheating on college entrance exams and funneling money…