Answer:
Option B). 10 cm
Explanation:
Distance between center and the focus of an ellipse is given by the formula,
c² = a² - b²
where, a = length of the major axis
b = length of the minor axis
and c = distance between focus and center
If c = 6 cm, b = 8 cm,
6² = a² - 8²
a² = 6² + 8²
a² = 36 + 64
a² = 100
a = 10 cm
Therefore, length of the major axis is 10 cm.
Option (B) is the answer.