San Franciscans of the 1890s mocked the claim that declared Los Angeles a world city, yet within twenty years a powerful municipal will had made this boast a reality .

A. yet within twenty years a powerful municipal will had made this boast a reality
B. yet within twenty years a powerful municipal will made this boast a reality
C. yet a powerful municipal within twenty years will make this boast a reality
D. yet this boast had become a reality within twenty years because of a powerful will municipally
E. yet within twenty years a municipal will had made this boast a powerful reality

[spoiler]OA Later
Please explain your reasoning.[/spoiler]