You have an empty 64 bit PCI slot in your computer. What can you install in it?

A. A single 64 bit adapter card

B. A single 32 or 64 bit adapter card

C. A single 64 bit adapter card or two 32 bit adapter cards

D. A single 64 bit adapter and an 8 bit adapter

To determine what can be installed in an empty 64-bit PCI slot in your computer, you need to understand the compatibility and specifications of PCI slots.

PCI (Peripheral Component Interconnect) slots are expansion slots found on the motherboard of a computer. These slots provide a way to add additional hardware components to the computer.

In this case, since you have an empty 64-bit PCI slot, you can install various types of adapter cards. However, the specific options depend on the width and compatibility of the slot.

Here are the possible options:

A. A single 64-bit adapter card:
This option means you can install a single adapter card specifically designed for a 64-bit PCI slot. The card should match the width and compatible specifications of the slot.

B. A single 32 or 64-bit adapter card:
This option allows you to install either a 32-bit or a 64-bit adapter card in the 64-bit PCI slot. The slot is backward compatible with 32-bit cards.

C. A single 64-bit adapter card or two 32-bit adapter cards:
With this choice, you can install either a single 64-bit adapter card or two 32-bit adapter cards in the 64-bit PCI slot. Some motherboards provide slots that can accommodate either a single 64-bit card or two 32-bit cards.

D. A single 64-bit adapter and an 8-bit adapter:
This option is not applicable to a 64-bit PCI slot. An 8-bit adapter is meant for a different type of slot, such as an ISA slot.

Therefore, the correct option is either A. A single 64-bit adapter card or B. A single 32 or 64-bit adapter card, depending on the specific motherboard specifications.