The parallel bus arbitration technique uses an external priority encoder and a decoder. Suppose, a parallel arbiter has $5$ bus arbiters. What will be the size of priority encoder and decoder respectively? $4 \times 2 , \: 2 \times 4$ $2 \times 4 , \: 4 \times 2$ $3 \times 8 , \: 8 \times 3$ $8 \times 3 , \: 3 \times 8$

Consider the poset $( \{3,5,9,15,24,45 \}, \mid).$ Which of the following is correct for the given poset ? There exist a greatest element and a least element There exist a greatest element but not a least element There exist a least element but not a greatest element There does not exist a greatest element and a least element