If I’m not mistaken, the answer is C.
Answer:
B. 3
Step-by-step explanation:
To find the value of c, substitute the x and y values of the given point into x and y of the equation, then isolate c. Since that given point is (2,5), substitute 2 for x and 5 for y:

Thus, c = 3.
78 is the significant figure because in maths 0's are not considered significant. Read more into significant figures to help you out.
Answer: D) Adding heat to the reaction