padi IDC theory – SCUBA physiology

Q1
What is the most likely cause if your buddy acting foolishly at depth?
c.)  Nitrogen narcosis

Q2
__________ can be detected in the body, using a Doppler detector, before any signs and symptoms of decompression sickness 
a)    High blood sugar levels
b)   Silent bubbles
c)    Increased activity in the haemoglobin
d)   Slower brain function