As Part of a Lab Exam,you Are Given a Vial

Multiple Choice

As part of a lab exam,you are given a vial of orange crystals.When you add them to pure,neutral pH water,the pH changes to 13.Other tests show that the crystals consist of a single chemical.You could conclude the chemical is 

A) a weak acid.
B) a weak base.
C) neutral.
D) a strong acid.
E) a strong base.