$14-$ TCP is said to be reliable end$-$to$-$end byte stream service, that means

a$-$ If only a small amount of data is available, TCP does not wait forever for additional data

b$-$ TCP avoids sending a segment that is larger than the maximum transfer unit

c$-$ TCP guarantees that byte stream that is put into communication channel on one end comes out unmodified at the other end

d$-$ TCP beaks data into small segments