They would fall with the same acceleration
It holds more weight in the regular water.
I’d say b is the better option because d is starving yourself which creates unhealthy habits, c would cause yo yo dieting or binging because you treat food as a reward which is a toxic mindset, and a same explanation. I wish there was an answer to just track what you eat, have daily exercise and enjoy in moderation, though.
Answer:
Approximately 
(assuming that external forces on the cannon are negligible.)
Explanation:
If an object of mass 
is moving at a velocity of 
, the momentum 
of that object would be 
.
Momentum of the t-shirt:
.
If there is no external force (gravity, friction, etc.) on this cannon, the total momentum of this system should be conserved. In other words, if 
denote the momentum of this cannon:
.
.
Rewrite to obtain 
. Since the mass of this cannon is 
, the velocity of this cannon would be:
.
