Multiple Choice, Single Answer

Read the passage and answer the question.

The modern sandwich industry has grown into a multi-billion-dollar global market, driven largely by convenience-seeking urban workers with limited lunch breaks. Pre-packaged sandwiches, once considered a poor substitute for home-cooked meals, are now engineered by food scientists to maximise shelf life without sacrificing texture. Bread staling, a major obstacle to freshness, is delayed through modified starches and controlled humidity packaging. Meanwhile, supply chains have become highly centralised, with a small number of factories producing millions of units daily for distribution across supermarkets and convenience stores. Critics argue this standardisation has reduced regional variation in fillings, while defenders note it has made affordable, safe food available to time-poor consumers who previously skipped meals altogether.