Vascular bundle with protoxylem towards the periphery is
A.Radial – xylem and phloem present on different radii.
B.Endarch – protoxylem is towards the medulla and metaxylem is present towards the pericycle.
C.Exarch – protoxylem is present towards the periphery(pericycle) and metaxylem is present towards the centre(medulla)
D.Closed – vascular bundle, in which cambium is not present between the xylem and phloem.
So, the correct answer is ‘Exarch’