Mira is much bigger than the Sun.
Only very massive stars will go through a supernova stage, causing the outer layer to explode away and the core to collapse in on itself, becoming very dense.
The answer is c 1386j
This calculator is very helpful I use it on my homework
https://www.omnicalculator.com/physics/specific-heat
I just solved similar type of question. You can refer to my solution which I have attached
Kinetic energy is the energy associated with the motion of an object. It's a scalar quantity, there is no direction associated with KE and it has no components.

.
Therefore Kinetic energy is 817.96J.