What happens when you install a 66Mhz, 32-bit PCI card in a 33MHz, 64-bit PCI slot?

A.
The 66MHz, 32-bit card operates at 33MHz in 64-bit mode.

B.
The 66MHz, 32-bit card operates at 66MHz in 32-bit mode.

C.
All 33MHz, 64-bit cards on the PCI bus operate like 33MHz, 32-bit cards.

D.
The 66MHz card operates at 33MHz.

Explanation:
The rules that govern the use of PCI cards are as follows:
A 66MHz PCI card can be used on a 33MHz PCI bus.
A 33MHz card in a 66MHz PCI bus automatically operates at 33MHz.
A 32-bit PCI card can be installed in a 64-bit PCI slot.
A 64-bit card can be installed in a 32-bit slot and will work in 32-bit mode.
A PCI bus can be so heavily used that it becomes a performance bottleneck. It is best to plan for
optimal performance when configuring the PCI devices.
To provide optimal configuration:
1. Match 66MHz slots with 66MHz devices.
2. Match 32-bit slots with 32-bit devices.
3. For the remaining devices, proceed as follows:
If you have available 32-bit slots, place the minimum number of 64-bit devices in the 32-bit slots,
using the devices with the lowest throughput.
If you still have more devices than available 64-bit slots, the 66MHz slots will have to run at
33MHz (64-bit).