Why is some memory installed in pairs?

You’re planning a memory upgrade on one of your laptop computers, and you notice that the manufacturer requires that memory modules are installed in pairs. Why might this requirement be part of the memory specifications?

A) The memory modules are redundant. If one fails, the other module will continue to operate.

B) The memory modules are dual-sided, but the laptop motherboard can only access one side of the memory to save battery power.

C) The laptop motherboard doubles the available memory throughput when two memory modules are used.

D) The laptop motherboard was engineered before large-capacity memory was widely available.

E) The laptop manufacturers are in secret pacts with the memory manufacturers to increase the sales of memory modules. It’s an international conspiracy!