Introduction:
Dynamic Random Access Memory (DRAM) is a type of memory used in computers and electronic devices for storing and retrieving data. It is a volatile memory, meaning that its contents are lost when the power is turned off. DRAM is widely used due to its high storage density and low cost compared to other memory technologies.

Explanation:
The correct answer is option D - "Information is stored in a capacitor." Let's understand why this is the correct answer:

1. Information Storage:
- In a DRAM, each memory cell consists of a capacitor and a transistor.
- The capacitor represents a binary digit (0 or 1) based on the presence or absence of charge.
- When the transistor is turned ON, the charge in the capacitor represents a logical 1, and when the transistor is turned OFF, the absence of charge represents a logical 0.
- Therefore, the information is stored in the form of electrical charge in the capacitors.

2. Read and Write Operations:
- DRAM allows both read and write operations.
- During a read operation, the voltage across the capacitor is sensed, and the stored charge is detected as a logic level.
- During a write operation, the voltage across the capacitor is changed based on the desired logic level, either by charging or discharging the capacitor.

3. Simultaneous Read and Write:
- Unlike Static Random Access Memory (SRAM), DRAM cannot perform simultaneous read and write operations on the same memory cell.
- This is because the read and write operations require different voltage levels and circuit timings, which cannot be performed simultaneously on a single cell.
- However, read and write operations can be performed simultaneously on different cells of the DRAM array.

4. Periodic Refreshing:
- One of the major drawbacks of DRAM is its inherent charge leakage.
- The charge stored in the capacitors gradually leaks away over time, leading to data loss.
- To prevent data corruption, DRAM requires periodic refreshing.
- The refresh operation involves reading each memory cell and rewriting the same data to refresh the charge in the capacitors.
- This process is performed automatically by the DRAM controller at regular intervals.

Conclusion:
In conclusion, the correct answer is option D - "Information is stored in a capacitor." DRAM stores data in capacitors, allowing read and write operations to be performed. However, simultaneous read and write operations on the same cell are not possible, and periodic refreshing is required to maintain the stored data.