NineEighteen,
I cannot agree with your definition of dihedral.
The term (lateral) dihedral is commonly abreviated to "dihedral". It refers to the situation in which the wings or tailplane are angled upwards from root to tip. Its principal purpose is to increase lateral stability.
The term "longitudinal dihedral" refers to the relationship between the angles of incidence of the wing and tailplane (or canard). This is one of the factors that contribute to longitudinal stability.
The term "dihedral effect" is commonly used to refer to the way in which wing sweep back increases lateral stability, making the aircraft behave as if it had a greater degree of dihedral.
The question referred to in this string has already been challenged by EPTA and CABAIR (CCAT). If other schools have also challenged it, then it is likley that it will be scrapped and the points awarded to all students who took the exam.
All of the FTOs will be informed of the results of all such challenges about two or three weeks after the exam.