Answer :
Cambridge English Dictionary defines "assert" as "to behave in a way that expresses your confidence, importance, or power and earns you respect from others."
The correct answer is :
B. She forcefully asserted her view that something needs to be done to reduce crime in the city in front of city council.
All the other options are unsuitable as they have the following definitions according to the Cambridge English Dictionary :
A. Snarl (snarled) - "(especially of dogs) to make a deep, rough sound while showing the teeth, usually in anger or (of people) to speak or say something angrily and forcefully."
C. Comment (commented) - "something that you say or write that expresses your opinion."
D. Murmur (murmured) - "to speak or say something very quietly."