What does DRAM require that makes it different from SRAM?

The correct answer highlights a fundamental difference between DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory). DRAM requires regular refreshing because it stores each bit of data in a separate capacitor within an integrated circuit. Capacitors tend to leak charge over time, which means that if the data is not refreshed periodically, it can be lost. This refreshing process is essential for DRAM to maintain the integrity of the stored data.

In contrast, SRAM does not need to be refreshed as it uses a different method of storing data, relying on bistable latching circuitry instead of capacitors. This structural difference results in SRAM being faster and more reliable for certain applications, especially where speed is critical, but also more expensive and power-hungry compared to DRAM.

The other choices touch on characteristics or applications of SRAM and DRAM, but they do not directly address the key aspect of data retention and refreshing that distinguishes DRAM. For example, while DRAM is typically slower than SRAM and can have higher power usage depending on the design and application, the necessity for refreshing is the defining characteristic that makes DRAM unique.