D............................
Their average velocity is 0.98 m/s east.
Explanation:
The average velocity of an object is defined as the ratio between the displacement and the time taken:

The displacement is a vector connecting the initial point to the final point of motion: so, being displacement a vector, velocity is a vector as well, having the same direction of displacement.
Here, Heather and Matt walk 2.0 km eastward, so their displacement is
d = 2.0 km = 2000 m (east)
While the time they took is

Therefore, their average velocity is

And the direction is the same as the displacement (east).
Learn more about average velocity:
brainly.com/question/5248528
#LearnwithBrainly
Your answer would be C.
A step-up transformer is a transformer that raises voltage from main to secondary by having more secondary winding turns than primary winding turns.
Hope this helps; have a great day!