If We Assume the Traditional View of Existential Import, Why

Multiple Choice

If we assume the traditional view of existential import, why is the following syllogism invalid? No university is an elementary school.
Some educational institutions are not elementary schools.
Some educational institutions are not universities.

A) undistributed middle
B) illicit major term
C) illicit minor term
D) two negative premises
E) negative premise with affirmative conclusion, or negative conclusion with no negative premise