Why do Ruben, et al $(2021)$ argue there is an increasing need for attention to leadership within higher education?

Select one:

a$.$ because of higher education's aging workforce

b$.$ many of the principles of effective leadership proven to be of value in other sectors have received little emphasis in higher education, but should

c$.$ higher education is unique and therefore presents special leadership challenges which require attention

d$.$ both a and c

e$.$ both b and c