Nuala Recently Acquired an Interest in a Piece of Land

Nuala recently acquired an interest in a piece of land called Blackacre. A chain of title

A) is relevant only if she is a mortgagee and there is at least one other mortgagee.
B) was probably used by a surveyor to accurately measure the boundaries of Blackacre.
C) is one of the three principles that form the notion of indefeasibility.
D) need not be proved if Blackacre is located west of Manitoba.
E) is relevant only if she also wants to buy another piece of land that is located next to Blackacre.