You Have Flown to NYC to Have a Discussion with a Technical

Multiple Choice

You have flown to NYC to have a discussion with a technical executive of a too big to fail bank. You are having a discussion about blockchain algos and the customer is asking what are some disadvantages of using a POW algo?

A) Centralization of blockchain control
B) Only use case for computational power is blockchain
C) Large expenditures for computational power
D) Not profitable for miners
E) 51% attack mitigation