25. 汽車電路常用電晶體作為開關迴路，大多採電晶體之特性曲線之那一區工作？(A)作用區(Active re gion)和崩潰區(Breakdown region)(B)飽和區(Saturation)和截止區(Cut-off region)(C)截止區(Cut-off region)和崩潰區(Breakdown region)(D)飽和區(Saturation)和作用區(Ac tive region)。