Which of the following reasons is true with respect to the statement of "The maximum throughput performance of slotted-ALOHA is about twice that of simple/pure-ALOHA"? because transmission can start...

Extracted text: Which of the following reasons is true with respect to the statement of "The maximum throughput performance of slotted-ALOHA is about twice that of simple/pure-ALOHA"? because transmission can start only at the beginning of frames time periods in slotted ALOHA because collision detection is implemented (so transmitters stop transmitting if they find a collision) in slotted ALOHA because the performance of slotted-ALOHA is not exactly twice that of simple ALOHA because slotted ALOHA stations can send their packets synchronously.