The only Central American country with a long history of democratic government isA. Guatemala.B. Costa Rica.C. Nicaragua.D. Belize.

Let's see: Guatemala had a dictator, Efrain Rios Monnt. Costa Rica  is a little more complicated, but the government under Rafael Ángel del Socorro Calderón Guardi was repressive too, but in any case, Tinoco Granados was a dictator before that.Nicaragua had a dictator: Anastasio SomozaBelize: Belize seems to be the best answer, although it became independent only in 1981.