Answer:
Niche cost leader
Step-by-step explanation:
Since in the question it is mentioned that the Digby company shifts the focus to the segments of Thrift and Nano while on the other hand it also decreasing the cost so here the niche cost leader should be considered as it is focused on the specific segment also it concentrate on the price reduction i.e less the price charged by the competitor in order to gain the competitive advantage
hence, the second last option is correct