The phrase "impinge on" most probably means ______.

A．American society has failed to provide these institutions with adequate resources to meet their needs.
B．Though in difficulty, these institutions are determined to fulfill both research and teaching functions.
C．American society has relied too much on their institutions of higher-education to allow them for easy adjustment to all their functions.
D．More resources and efforts of faculty are needed for research work than teaching work.

A．many public institutions have to cut down enrollments of students
B．teachers are not qualified enough for satisfactory performance in classes
C．some institutions have to reduce the expenses on research
D．there is keen competition for resources and attention of faculty between public and private institutions