Why has the Liberal Democratic Party dominated Japanese politics for so long?

a. Opposition parties were radically different from the LDP, and their governments were too controversial.
b. Japanese voters tended to be liberal, preferring change and debate, and thus they always came back to the LDP.
c. The LDP party factions advocated policy alternatives rather than the promotion of leaders to positions of power.
d. It presided over the economic boom that began in the 1950s and was able to argue that it was the party of experience and economic prosperity.

d