Option A
The equation of ellipse in standard form is

Solution:
Given, We have to write an equation of an ellipse in standard form with the center at the origin
Given that vertex at (-3,0) and co-vertex (0,2)
The standard form of an ellipse is

where a is x- intercept and b is y – intercept.
We have vertex (-3, 0) and (0, 2) from these we can say that, x – intercept is – 3 and y – intercept is 2 . As we know that intercepts are the respective values when other variables becomes 0.
Now, let us find our ellipse equation:

Hence, the standard form equation is

Thus option A is correct