Which sentence is written correctly with matching verb tenses? a. when i was president, i ordered federal troops to enforce integration of the university of mississippi. b. when i was president, i will order federal troops to enforce integration of the university of mississippi. c. when i was president, i will have to order federal troops to enforce integration of the university of mississippi. d. when i was president, i order federal troops to enforce integration of the university of mississippi.