Opposite phyllotaxy is seen in
 

Cocept: Phyllotaxy is the positioning of leaves on the stem branches. Phyllotaxy can be classified as alternate phyllotaxy,   whorled phyllotaxy, and opposite phyllotaxy. In  Opposite leaves arise at each node and opposite to each other. Examples are caloptris, and guava. In whorled type, at each node, more than two leaves arise .ex: hydrilla. In an alternate phyllotaxy, leaves arise at each node in an alternate manner. Opposite phyllotaxy can be of two types one is opposite decussate and another one is oppositely superposed.  
Alternate phyllotaxy can be seen in sunflower, mustard and sunflower and whorled phyllotaxy can be seen in Alstonia.
Hence, the correct answer is B.