The ATX form factor is suitable for workstations that require high performance and expandability. ATX motherboards offer more expansion slots for multiple graphics cards and peripherals which is important for graphic design and 3D modeling tasks. Additionally, the larger ATX size allows for better airflow, which is ideal for systems that may generate more heat due to the high-performance components involved. The microATX is smaller than ATX with fewer expansion slots, not optimal when many are required. Mini-ITX is much smaller than both ATX and microATX, usually with only one expansion slot, which would not fulfill the requirement for multiple graphics cards. E-ATX (Extended ATX) is a valid option for even more room and expandability, but it's not listed among the choices provided.