Retrenching to a narrower diversification base is $\_\_\_\_\_\_$

A$.$ usually the most attractive long$-$run strategy for a broadly diversified company confronted with recession, high interest rates, mounting competitive pressures in several of its businesses, and sluggish growth.

B$.$ a strategy that allows a diversified firm's energies to be concentrated on building strong positions in a smaller number of businesses rather the stretching its resources and managerial attention too thinly across many businesses.

C$.$ an attractive strategy option for revamping a diverse business lineup that lacks strong cross$-$business financial fit.

D$.$ sometimes an attractive option for deepening a diversified company's technological expertise and supporting a faster rate of product innovation.