Procter & Gamble $($P&G$)$ used to be a big name in the food business since it sold everything from cake mixes to juice. However, $P$&$G$ reconsidered its strategy regarding what business it would do and what business it won't do$.$ It decided to focus its resources on its core business of household, beauty, and healthcare products. It thus began selling off products and brands that did not relate to the core business, a process that was completed when P&G sold the Pringles line of potato chips to Kellogg for $$2\mathrm{.}7$ billion. Which of the following best explains P&G$\text{'}$s strategy?

Corporate$-$level strategy.

Industry$-$level strategy.

Firm$-$level strategy.

Single business strategy.