Which type of bacteria will multiply at temperatures between 23 and 68 degrees?

The correct answer is psychotrophs. These bacteria are capable of growing and multiplying at a wide range of temperatures, including the moderate range of 23 to 68 degrees Fahrenheit. Psychotrophs thrive in environments that are typically cooler, such as refrigerators, but they can also adapt to warmer temperatures, making them particularly important in food safety. They can cause spoilage in foods stored at higher temperatures than recommended.

Mesophiles, while they do grow well at temperatures typically between 68 and 113 degrees Fahrenheit, do not thrive in the lower range specified in the question. Thermophiles prefer much higher temperatures, usually above 113 degrees Fahrenheit, and are not relevant in this context. Psychrophiles are adapted to cold environments and typically grow well at temperatures below 50 degrees Fahrenheit, which also does not align with the range provided.