The correct answer is: a) Hunting-gathering and shifting cultivation.
Prehistoric communities in the Mizo hills likely practiced a mix of hunting-gathering and shifting cultivation. This is because the Mizo hills are a mountainous region with a tropical climate, which is ideal for both hunting and gathering. The people who lived in the Mizo hills would have hunted animals such as deer, wild pigs, and birds, and gathered wild fruits, vegetables, and nuts. They would also have practiced shifting cultivation, which is a type of agriculture in which land is cleared for cultivation for a few years and then left fallow for several years to allow the land to regenerate. This type of agriculture is well-suited to the mountainous terrain of the Mizo hills.
Option b) is incorrect because large-scale agriculture and animal husbandry are not well-suited to the mountainous terrain of the Mizo hills. Option c) is incorrect because seafaring and trade are not activities that would have been possible for prehistoric communities in the Mizo hills. Option d) is incorrect because urban living and manufacturing are not activities that would have been possible for prehistoric communities in the Mizo hills.