TCP is a sliding window protocol. This means. а. there can be more than one segment "in flight" (sent but no ACK has been received) at a time. O b. the TCP retransmission timer slides up as ACKS are...

Extracted text: TCP is a sliding window protocol. This means. а. there can be more than one segment "in flight" (sent but no ACK has been received) at a time. O b. the TCP retransmission timer slides up as ACKS are received. O c. there can only be one segment outstanding (sent but no ACK has been received) at at time.