|A) Baby AT||B) AT|
|C) ATX||D) All the above|
ATX (Advanced Technology extended) is a motherboard form factor uses one 20 pin connector.
ATX is developed by Intel in 1995 to improve on previous de facto standards like the AT form factor. It was the first major change in desktop computer enclosure, motherboard, and power supply design in many years, improving standardization and interchangeability of parts.