Which networking port should the administrator check for connectivity from the host to vCenter Server?

An ESXi 5.x host disconnects within 60 seconds after the administrator adds it to the
vCenter Server inventory. The administrator determines that the issue could be related to a
networking problem. Which networking port should the administrator check for connectivity
from the host to vCenter Server?

A.
902

B.
903

C.
443

D.
9443