Upon reaching là gì

Upon reaching [A] the destination, a number of personnel is [B] expected to change [C] their reservations and  proceed [?

Upon reaching [A] the destination, a number of personnel is [B] expected to change [C] their reservations and  proceed [D] to Hawaii.

A.  reaching

B.   is

C.  to change

D.  proceed

Đáp án   B is -> are
A number of + Npl + Vpl
Personnel is Npl