Answer:
C
Step-by-step explanation:
The sum of distances from any point on the ellipse to each foci equals a certain amount, no matter what point on the ellipse it starts from. The foci are on the major radius of the ellipse (the longer length of horizontal/vertical). The foci are of equal distance from the center, with one on each side.
If you wanted to find where the foci are using the major and minor radius, we can find that, representing the distance between the center and any foci as g,
g² = major radius² - minor radius². Then, the distance between the center and the foci is equal to g